I'm liking where do you want to get with your art. Those chubby characters are showing traits of a cute and delightful style that I find quite interesting.
Right now, I'd advise you to practice as much as you can to improve in a couple of things I think you should tackle ASAP: A steady line, which will fit your cutey characters better and a coherent set of proportions that will enhance the charm of your creations ( then you'll have to come up with "anatomy tricks", but a set of proportions is primary to that.).
To improve on the first, only time and practice will work. For the second, experimenting with "wired" bodies and shapes is the way, but you can also try to have a look at artists akin to your style and try to get an understanding of what makes their figures work.
I really hope I can see you improving and kicking ass soon. Best wishes!
AlmightyPenis
coppin a feel