Creating curved ribbons in Illustrator is not one of those things that makes a lot of sense when you think about how to curve them and make them look real.

But this makes it easy for both a curved ribbon and a ribbon turn as well.

Start with a rectangle, set it to no fill, but with a stroke. 

Select just the upper left corner with the Direct Selection tool and activate the Live Corner Widget.

Drag the corner widget into the center as far as it will go to form a rounded corner.

Select the lower right corner point with the Direct Selection Tool and delete. This will remove the right and bottom line.

Duplicate the line.
Select both line and Join them together.  Object>Path Join. Join twice to close both open ends. (COMMAND + J)

Switch the fill with the stroke. 

Chose the Reflect Tool and reflect the ribbon, click COPY to get a duplicate.

Change the color of the second ribbon to a darker color.

Send the darker ribbon to the back to make it look like it wraps around.

Create another rectangle, keep the same width as the height of the existing ribbon. Fill with the darker green.

Select the upper right of the light green ribbon with the Direct Selection tool and move it to the right side of the dark green rectangle.

Duplicate the ribbons and move them to the upper part of the vertical rectangle.

Select the lower right corner of the upper ribbon with the Direct Selection Tool and move it to the outside edge of the vertical rectangle to create the fold-over.

Upper and lower sections with curved ribbons with the center section with the fold-over.

Final ribbon with curves and roll-overs.

Some added elements to create more of an infographic!

Creating a paper cut-out look is quite easy using the Appearance Panel and the Width Shape tool.

We are going to create some weather icons for fun and use the Graphic Styles Panel to capture these setting and apply them easily later.

Start with a circle. holding SHIFT to make a perfect circle.

Use OPTION and click and drag the circle to create a duplicate and mov e it half way over the other circle.

Use COMMAND + D to duplicate it further.

Copy another set above the existing set to create a cloud.

Use the Pathfinder to Unite the circles, or chose Effect>Pathfinder>Add.

Open the Appearance Panel from the window menu. Add a white stroke, 9 pt, and click on the stroke OUTSIDE of the path by checking the button highlighted in red in the stroke panel.

From the bottom of the Appearance menu, choose the FX menu. Stylize, Drop Shadow.

Apply a drop shadow to the shape. 

Make sure you drag the drop shadow effect UNDER the fill section of the Appearance panel or else it will apply the drop shadow to the Stroke, just like you would move layers in the layers panel from one location to another.

Here is the result. Stroke is outside the shape and the drop shadow outside as well. If you apply the drop shadow to the stroke, it will appear on top of the fill.

Open the Graphic Styles Panel from the Window Menu and drag the cloud into the Styles Panel and it automatically adds the attributes (Stroke, Fill, Drop Shadow) into the Panel for future use.

Draw a circle and click on the new Style you just created in the Graphic Styles Panel and the circle will have all those attributes.

Select the sun and change the fill to yellow, it will keep all the other attributes (stroke and drop shadow). Send the sun to the back. Then add a few stars and click on the style from the Graphic Styles panel to apply all the attributes to the stars, then change the fill color to dark blue.

Add some rain drops. Inside they are filled with white then have an inner glow added.

Add an Inner Glow to the Rain Drops. Chose the FX button on the bottom of the Appearance Panel and choose Stylize>Inner Glow. Set the fields as shown with a light blue fill. You can drag the new rain drops into the Graphic Styles Panel to capture the rain drop settings for future use.

Drawn an arc, add a white stroke to the arc, about 20 pt.in this case. 

Click the FX button on the Appearance Panel and choose Stylize>Feather. Set the feather on the stroke to .2 cm.

Use the Width Shape Tool (SHIFT + W) and pull out the center handle on the curve to make it wider, and pull in on the ends to make them thinner.

Here is a close-up of the handles you get using the Width Shape Tool on the Path. The handles are what you pull in and out to pinch or widen the lines.

Drag the feathered arc into the Graphic Styles Panel.

Make another arc on the clouds, then click on the Feather Style you just created in the Graphic Styles Panel to get the arc to feather and pinch at the ends.

Start your holiday light by drawing a circle, hold SHIFT to make it a perfect circle.

Fill the circle with a color.

Use the Direct Selection Tool to select the top most point of the circle. Hold SHIFT and UP ARROW to make the more like the shape of a light bulb.

Draw a rectangle at the bottom of the light, making sure it is centered on the bulb.

Select the bulb and the rectangle base. Open the Pathfinder Panel (Window>Pathfinder) and choose the Unite button to combine the two shapes into one.

Create a rectangle and place it over half of the shape, making sure that the long edge of the rectangle is directly centered in the bulb.

Select the bulb and the rectangle and choose the Minus Front button in the Pathfinder panel.

The result with be half a blub.

​Under the Effects Window, choose 3D > Revolve.

The 3D revolve dialog box will open. Click the Preview button at the lower left of the dialog box.

Use the drop down menu (highlighted in red) and set the edge to be Right Edge. This will revolve around the right edge of the bulb.

The bulb will render on screen. If you want to rotate the bulb, use the 3D cube in the upper left, keeping in mind the face highlighted in Blue is the front face. Grab the cube and move it around to see how it rotates the bulb on the X, Y and Z axis.

​Click OK

If you want to change the color of the bulb, select the bulb with the selection tool and choose another fill color from the Swatches Fill Panel. It will automatically render in that color. Duplicate it and make several bulbs that are different colors.

To edit the rotation of the bulb, open the Appearance Panel under the Window menu. Select the bulb and then click on the 3D Revolve link in the Appearance Panel.

You cannot go back under the Effects menu and choose 3D revolve again, it will remove the 3D and you will start over.

Creating the Light Cord to attach the lights.

Draw a straight line, make it dark green. This line has a stroke of 8 pts.

Duplicate that line and leave a bit of space vertically between the 2 lines.
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Add a 3rd line, make that a bit darker green and place it behind the other two lines (COMMAND + SHIFT + [)

Select all 3 lines and open the Brushes Panel from the Window Menu.

Click on the Brushes drop down menu (the cheese grater) and choose New Brush…

Select Art Brush and click OK.

Name the brush in the next Dialog Box and click OK.

Now draw a line using either the pencil tool, the pen tool or with the brush tool.

With the line selected, choose the green “power cord” you created in the brushes panel. You can adjust the width of the cord by adjusting the point size of the line.

Draw path to make it look like it connects with the lights.

Lets make a Snowflake.
​Start with a line. Add a color from the Swatches panel and beef up the stroke weight to 7 pt.

Add more elements to the shapes.
​I added a half circle, then a Y shape, making sure everything is centered on the main center of the line.

Select all the items you have created and click on the Rotate Tool in the Tool Bar (R is the shortcut)
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​Hold OPTION and click on the base point of the art work. It will open the rotate dialog box.

Choose an angle of rotation that is even divisible into 360°. In this case I chose 45° and then click COPY. Don’t click OK or it will not copy the selected items.

​Click COMMAND + D to repeat the rotate command several more times as the artwork repeats around the center point.

By changing the initial set of items, you can change the look of a snowflake quickly. 
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​I have several snow flakes shown with just some subtle changes to the initial artwork, then rotate and copy it.

Lets make a pine tree, with a slip shadow. Darker on one side to give it some implied dimension. Simple. Then add some nice snow to it.

Start with the Polygon Tool.
Draw a Polygon, do not let off the mouse button. If you do click off, you will need to draw the Polygon again.

When drawing, with the mouse held down, use the down arrows on the keyboard to get 3 sides. Up arrow adds sides, down arrow takes sides away. Fill the shape with green.

With your new triangle selected, hit the Return key.
That will bring up the Move Dialog Box.

Click the Preview on in the lower left corner to see that actions when you put the values in the Position sections.

Set the Horizontal to O and the vertical to 1.5. Or enough to move the triangle down enough to create an off set like a tree would have. 

Click OK when you move the triangle down.
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When the triangle is moved down, and copied as shown to the right, then use COMMAND + D to duplicate the triangle 4 more times.

When you have several triangles as shown, select all the triangles with the Selection Tool and open the Pathfinder Panel.
Window> Pathfinder.

Choose Unite to make all the triangles one composite shape.

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With the triangles now United as one, choose the Effect Menu>Distort & Transform>Free Transform.

Select the base and pull the bottom side out to form a wider base and click OK.

Draw a rectangle over the right half of the tree. Add a fill of a darker green. 

With both the tree and darker rectangle selected, open the Pathfinder Panel and choose Divide. 

When you click the Divide in the Pathfinder Panel, then choose Object>Ungroup. Use the Selection Tool to select the extra dark green outside the tree and click Delete.

This will leave both sides of the tree as separate shapes.

Select each shape with the Direct Selection Tool.

Pull the Live Corners into the center of the tree to round the corners.

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Using the Brush Tool, choose no fill, a stroke color of white and 1 pt to start with. Add some dots of snow, then increase the brush size a bit to get bigger dots of snow.

​Enjoy your tree!