If you have wanted to put a bevel on a shape, type or anything that you create in Illustrator, here it is. This will show you how to create a bevel on any shape, square, curved or round.
Pick a typeface that you want to bevel
Choose Type>Outline Type to turn the active type into shapes. Ungroup the type.
Create divider lines on the shape to begin. To find the centers, make sure your Smart Guides are on under the View Menu.
If the Smart Guides do not show the centers of the shapes, create a rectangle the width or height of the shape and use the center of the rectangle to find the center.
Draw lines from the corners. They can extend beyond the corners. Hold the SHIFT key when drawing lines to get them to be at a 45° angle. In some cases, the angles will not be a 45° in all cases. The key is to have the angled lines meet at the center line.
When all the lines are drawn, make sure all the lines touch but do not go over their intersection points. The best way to check this is to go into Outline Mode under the View Menu to see up close how all the lines meet.
Select all the shapes, use the Divide Mode in the Pathfinder Panel. Ungroup all the shapes.
Select the shapes and add lighter colors to the highlight sides,
Fill with darker colors on the shadow sides
Here you have the beveled shape.
To create a bevel on a round or curved shape, the same principals apply. Find a center line on the vertical and horizontal lines. Draw the angle lines from the corners.
On the curved areas, create a rectangle on the width of the shape. Use the center of the rectangle to find the center of the width. Draw a line from the center of the rectangle to the center of the vertical.
Use the Curvature tool to curve the line to match the shape.
Repeat the process on the lower portion of the curve.
Select all the shapes, use the Divide Mode in the Pathfinder Panel. Ungroup all the shapes. Apply the lighter and darker colors to the sections.
For angled shapes, find the center of the shapes.
To find the center of the arms, draw a square.
Rotate the square 45° and scale the square so the points of the square touch the edges of the arms. Now you have the center to draw the line from
Use the Direct Selection Tool to select and remove the upper part of the square (not needed) then select the bottom point and move it over to the center line.
Repeat the process on the other arm.
Go into Outline Mode to make sure all the lines touch but do not overlap. Select all the shapes, use the Divide Mode in the Pathfinder Panel.
Ungroup all the shapes. Apply the lighter and darker colors to the sections.
For square of rectangular shapes, this is much easier. You can find the centers of the rectangles and draw 45° angles to locate the centers if needed.
Here is the shape in Outline Mode.
The lines are easier to see and adjust in Outline Mode.
And the final shapes, all with the bevel applied. You can go into Outline Mode and move the lines to change the bevels after they are completed.