How to smooth sides
This will teach you how to smoothen the sides of a shape.
Step 1: Rectangle
Create a rectangle
Use either the line tool or rectangle tool to create a 2d rectangle
Using the line tool, make a line in the middle of the rectangle and "cut" the 2 smaller rectangles in half again. Repeat the number of lines that you draw for the amount of detail that you want.
Make a line perpendicular to the corners of the rectangle and repeat for the amount of rectangles you have.
Using the "move" command, drag the endpoints in the desired direction.
To smooth the edges, using the eraser tool, press ctrl (control) to smooth desired edges out.