Start by making the backboard for your wall basketball hoop. Trace out the shape on a piece of cardboard and cut it out using a safety razor. Paint it or use markers to decorate the backboard anyway you'd like.
Next, cut a length of 6 gauge copper wire to 2 feet long. The copper wire is soft enough to bend with your hands but rigid enough for a mini basketball to rebound off of. Use your hands to bend the wire into a circle. This will become your basketball hoop. Test it with your basketball to make sure the mini basketball can fit through the hoop nicely.
Now take a regular basketball net and cut down the side of it. Shorten the net by cutting off the bottom half and make it narrower by cutting out part of the side of the net. Glue it back together where the seam comes together and tie it to your copper hoop.
Glue the hoop you made in Step 2 to the basketball backboard you made in Step 1. Now just hang it on your wall and start enjoying your wall basketball hoop!