one thing that really helped me was finding the right medium. You can look at the art on-site and say, 'wow, I want to draw as good as that', but it's never going to happen if you don't have the right tools. I used to be a hand drawer- and I'm not bad at it either, but I would have to take a picture of it (or scan it, but who has the time) and then upload it. The whole process would make my details suck, and my shading make absolutely no difference, and to put it short, it was ugly.
digital art looks pretty- but it's a lot harder than hand drawing. I myself have burned countless hours producing crap on MSPaint, and then getting frustrated and quitting. Computer art was certainly not easy. But then, I got a tablet. Drawing on an iPad is just like drawing on paper for me- but it looks nicer and is way easier and faster to make. That's how I've improved.
Long story short, find what works best for you. If you like hand drawing but don't like the way your pictures turn out in a picture, try tablet drawing. If you're a computer / vector genious, use a computer. No matter what, use what's most comfortable technologically, because then you can draw your best.
As for your picture, Espeon's head looks a bit too wide- if you could fix that, it would look a lot nicer. Keep up the good work.