Step 2 Select all (Cmd/Ctrl + A), then Effect > 3D > Extrude & Bevel in the top menu. Enter the values 79°, 0°, 0°, with an extrude depth of 20pt. This flattens out the circle and raises the steps for a convincing effect.
Step 3 Group all the parts into their individual step shapes and begin arranging them in ascending order. The Extrude & Bevel filter did the 3D work for us. All we have to do is create the feeling of height by nudging each step up a few notches, until we’re happy with the result.
Step 4 Once you have one side of steps arranged in the way you want them, group them together. Duplicate this, then use the Reflect tool (O) to flip the group horizontally. You should now have two sets of steps.
Don’t worry about colours at this stage. All we need is enough contrast in the shapes to give us clarity. We’ll look at our colour schemes later.