Create icons can be made a lot easier when using a Grid. Illustrators grid is easy to set up, your creations can snap to the grid making icon create a quick and easy task. See how easily this abstract shower head icon can be created.
Set up the grid structure that will appear behind the artwork. Go to Preferences > Grids & Guides. I use millimeters as they are base10 so easy to create content in units of 10. Set the Guideline every at 10mm. Set the subdivisions as 10.
To turn the underlying grid on your document, choose View > Show Grid. Choose Snap to Grid so the shapes will snap to the grid automatically.
Start you creation by creating a rectangle 10 units wide, 2 units high. Below that create a rectangle 6 units wide, 2 units high. Repeat both shapes again.
When you see the grid, you will notice that the main guides are a bit bolder and the subdivision are a bit lighter. This gives you a good idea of the block of 10 units and makes it easy to use that as a reference when creating.
Create a rectangle 46 units wide, 5 units high. Create another rectangle 46 units wide , 3 units high 2 units down from the upper rectangle.
Create "drips" using rectangles that are 2 units wide. Make each one a varied height to create the water drip effect. Start them 2 units in from the edge.
Add a 3 unit wide, 2 unit high rectangle at the far left between the two large rectangles. Make the lower large rectangle 50 units wide (2 units longer on each side).
Select all the shapes and use the Unite mode in the Pathfinder Panel to join them together as one unit.
Select the lower edges of the drips with the Direct Selection Tool to activate the Corner Widgets. Pull the corners in to round them.
Select the ends of the longest rectangle with the Direct Selection Tool and pull in the Corner Widgets.
Select upper left and right corners of the largest rectangle with the Direct Selection Tool and pull in the Corner Widgets.
Select the right end of the inside slit with the Direct Selection Tool and pull in the Corner Widgets.
Select the top ends of the water drips with the Direct Selection Tool and pull in the Corner Widgets.
Select the outer ends of the threaded part with the Direct Selection Tool and pull in the Corner Widgets.
Select the inner ends of the threaded part with the Direct Selection Tool and pull in the Corner Widgets.
Select the line segment at the right middle and delete the line with the Direct Selection Tool. In the Stroke panel, round (hot dog) the ends of the stroke.
Add a few circles 2 units x 2 units. Increase the stroke weight and add a color to the stroke. Done!