Here are a few homemade craters. These are made from aluminum pot-pie pans. You can buy these in bulk from the grocery store for a few bucks. You will get more than you need. Flip the pans over and squash the middle down. Carefully shape them as desired as you smash them. I then cut the edges into irregular shapes. Glues on some rocks and apply some texture, then paint.

A comparison with a small Moonscape crater.

Here is a cluster if pie pan craters with the cluster crater from the Blastscape set.
I built these years ago but never got beyond the base coat stage. With all the work I have done on the GW stuff inspired me to finish these up.