Just to make it clear; I'm not being rude here, I'm just trying to give you criticism that you might be able to use to improve your art in the future ^^
Most of these are quite boring, simply. For example the Gendactyl, it's just a recolor of Gengar and Aerodactyl's wings. It's so simple to make. Blazicross is a bit better, but you did a really sloppy job of editing it's arms. They appear on top of the hair, which doesn't make any sense. That sprite would need editing so that it'd look like the arms come through the hair, instead of on top of it. Pikamew is the best one here, but even then it's just average. I can't really point out any weak spots, though. Giraquaza is the same thing as Gendactyl, just a recolor and a quick add of wings. As for Garvafty, it just looks like an eyeless Garvantula with a Scrafty-shaped tumor on its head. The editing here seems, again, rushed, and the outcome is not very good.
I think the best way for you to improve would be to simply take more time with your sprites. Don't hurry, you have all the time in the world. Be critical. Instead of thinking 'meh this looks ok I guess I'll just stop here', think 'hmm this looks ok, but how can I make it look better?' Being critical is an important part of spriting, because if you're satisfied with everything you make, you won't improve. This might be a bit OOC, but I had such a situation myself. I made a sprite of my OC, Jake, maybe a month ago. Instead of just being happy with it, I decided to be critical. Just a week ago, I decided to look at it again, and attempt a better version of it. I made the sprite, and it looked much better than the first one. Even now I'm thinking about remaking it again. It's all about perfectionism, really.
Again, I'm not trying to be mean. There are many spriters on 'Charms, and the competition is pretty high. I believe that if you don't improve your sprites, your thread will just disappear in the masses. To end off this little ranty post; I like seeing good sprites, and I hope you can improve so I can return to this thread and see some nice material ^^