Step 5 Select the Width tool from the toolbar. In much the same as you would usually drag a Bézier point or an object to resize it, click at any point on a drawn line and drag away from the line. You can narrow or widen a line as much as you want.
Step 6 If you want to only widen one edge of the line, hold Alt when you click and drag. If you want to apply a stroke width effect to multiple lines, create it once, with that line selected, open the Stroke panel (Window > Stroke), open the Profiles menu and click the Add to Profiles button at the bottom left.
Step 7 The new Perspective Grid tool puts your flat artwork into perspective – as if pasted onto the side of a block. Create an element to use – here, I’ve made some mock billboards. Ensure your piece of artwork is grouped (select the artwork then hit Cmd/Ctrl + G). To open the grid, click the Perspective Grid tool in the toolbar.