Hey! I liked your dog picture, there was a lot of personality in it!
Anyway, I think you have nice starter figure drawings (not that I am any sort of master). My advice would be to do a small "stick" version of your figures before you do your main one to help sort out where things are placed.
I only erase when I work on the longer drawings (20 mins or more). There's not enough time to waste erasing in anything lower than that. Nor is it worth it.