first find out what you want to make (something easy)
(I took electrode+jumpluff as my first scratches, Bcause they all circles)
Then open paint+search the sprites (on bulbapedia)
copy past it+keep it close so you can see if yr pkmn still looks alot like it should be
(it's best u know a how yr pose of yr pkmn is going to look like)
then start with the outerlines (it's easy if it's a circle)
zoom alot out to see it it seems good or not and don't change suddenly from direction (for ex:u put 3 next to each other, the line above 2 next to each other, then the line above 1 dot) I hope you get what I mean...
then if you got the outer lines, do the outerl ines ofthe other details like the arms,legs,...