Ha ha ha, I've not done much critting for a while either - it's a learning experience for us both I guess! My comments are in the bolded yellow, just in case you didn't notice.
So yeah; examples
Ralts on Koffing action
Okay, I'm not even going to comment on this one, to be frank it scares me somewhat O.o
Revamps:
These, if I'm going to be honest, aren't even technically revamps. They're just recolours of old sprites using new colours, you can tell by the fact that the old shading is intact, and the outlines aren't shaded at all. Technically, a revamp is a sprite made to look like the new ones, size and proportion wise as well as shading, so it's got to be mainly scratched over the old sprite truth be told. Anyway, I'd say that the Ampharos is probably the best of the lot, since it look a little more natural, but the shades could do with a little more contrast. Did you make them yourself?
Doctor Octillery
This for the most part looks okay, but the band on its head could do with being slightly rounder and the outline shades on the white look a little too light.
Qwilfish Balloon Forme
A cute little edit, but the red on the bottom half of it is a bit too bright, and the shades contrast a bit too much. As daft as it sounds, you've done a pretty good job on the string, there's shading on there and it looks fairly smooth.
Recolours (of course)
The Nosepass looks great, not much I can say about it, but the Magneton needs a little work. The outlines, (especially on the magnets) are much too light and in some places are the wrong colour compared to the inside of the line.
Laser Skitty
This is a very random edit, and the animation seems to suit it. The lasers are going in the right direction, but maybe if you gave them some shading or added a glow around the edge it could look better.
Splices:
This little sprite is fairly decent, but as I've said a lot of times before some of the colours look wrong. The gas would probably look better a darker shade of yellow, and the shading on the top of it's head looks too bright.
Feel free to request, or not!
Overall, these are pretty good to start off with, but the main problem I've noticed is colour choice. You don't have to make them totally from scratch, you are allowed to use colours from other sprites until you get the hang of choosing the colours and shades to go with it. I'd quite like to see you do some more splices - they're a little more of a challenge and from there you can move onto scratching.