first off search your color palette, look for references or create your own palette from scratch. you must make sure that your palette cannot exceed 256 colors and that the first color (color #0) is for transparency!! i always search some palettes in lospec and pick a palette with the just right number of colors.
next, open grafx2 and sketch off a base doll using the colors of your choice (for truecolor images you can use clip studio or sai). here i did a sketch for kisumi osanai, an original character designed by satoshi wachigai that is likely to be the mascot of world kiss project...
finished your sketch for your base doll? great, now add a new layer and make a clean lineart with 1px straight or curved line whether the lines turn out jagged or not, then color and shade the doll just like this:
(sorry for the low gamut on the first two images!! the safe color mode at grafx2 was on before i finally turned it off)
now make the body pieces for your base doll. i use the grab brush tool to copy the head and arm to the next page, then i copy and erase the excess and draw the eyes and a couple of different hairstyles for the doll...
aaaaand all parts for your base doll are done! lets get to making clothes!
sketch off your outfit and draw the clothing pieces one by one... (i sketched a school uniform for the example)
then copy any clothing piece you want and draw the insides of it... (here i used kisumis underwear)
congrats, you have completed your doll and their clothing parts!!! now export your grafx2 project to gif and get to making the cel and kcf files!