It's good to keep the mindset that you're not good at art -yet.- You're on the right track, though, because you are practicing. Learning proportion and perspective will help you loads and loads, and pretty much the best way to learn that is to just do it. :D. You can poke through my account to see my improvement over time. I think I started this account a year ago, and most of what I put out was bad. But I made a deal with myself to just make stuff and out it out no matter how it looked. That plus learning new things and finding gentle and helpful critiquers equals inprovement.

Good luci!