Work on shading and anatomy, as well as doing more complex editing. Pikablu is pretty much just a recolor with copy and paste, and you shouldn't post sprites that aren't yours.
On your red blob sprite, all you did was take the darn paint brush, make it fatter, cover it up, and say DONE! Evolutions are much more complex, there are usually size and color changes (Raichu has a darker yellow, is bigger) new additions in the anatomy (The tail is a thin wire with a lightning bolt) etc.
Work on that as well, Aipup IS Aipom, just without a hand on the tail. Girafa is Girafarig, just without the head on the tail, as well as the stripes.