Lap sizes is all I make. I have made one twin size. I dont have the storage for large quilts.
I give alot of my lap quilts to family. They put them on the sofa back to use as a coverup when it is cold.
Baby quilts are popular since I have a lot of new babies in the family.
Smaller quilts give you a faster learning curve because of the variety of blocks made and much more practice at free motion and binding. Above all they are much more fun to make.
Big quilts are just to much hassle with the added bulk and I get bored with them.
Christmas quilts are great for gifts also.
I also make mine larger than lap size but not as big as a bed.