I make games and art, but really I just experiment. Any time I work on a project, I lay the foundation (core code and art) but then I do nothing. Maybe I just like to see how I would like to make something, and solving the "how" issue seems to be the only thing I have fun doing, not so much actually doing the work of making a game.
As a result, to try and encourage myself to actually complete any one project, I have done plenty of work seeing what looks good, works well, easy to make, and or is fast, and I think I have a few things you could try out. Oh, and I focus on free stuff only
3D
Blender, free program, Version 2.8 Beta is finally out and it is designed to be user friendly (or rather friendlier, 2.79b and before are know to have a steep learning curve). tons of videos online to learn from.
Go to smutbase for free blender nsfw content
go to blendswap for free everything that is sfw (20 downloads a month if not a paid for account)
learn to use cycle engine (blenders defualts to this... i think, anyway it is just part of blender, though eve may work even better and a lot faster with no lost of quality.)
you need characters, textures, backgrounds or locations, and know how to pose and maybe even rig a character. I have been home on winter break with only my old laptop and I am impress I can still sculpt with blender with no lag.
2D
If you want to make something more stylized
I recommend finding an art style you like (something that uses lines, no real shading, shading takes the most amount of time and is something you should avoid if you want speed and ease), vector or flash games are a good example.
If possible (and is my current experiment) use blender to make a VERY BASIC 3d model (it will be easy to make a model using different parts, like balls of clay, rather than try to make one mesh like a video game character. when you first do this, you will find any 2d that looks good, will look disturbing and bad in 3d, but that is fine, all you need to worry about are the outlines, and landmarks of the body to know where to draw things like belly buttons. but not something like eyes which get even more warped when trying to take 2d to 3d) you can use blender to make quick prototype poses.
Get Inkscape, a free online vector drawing program. using Lines, make an outline, or a closed shape (which you can fill with color). import the blender images and draw ontop of them (use different layers). a great way to make clean art. to improve further you can look to using lines where you change the mode of the line shape to ellipse, or use a custom Pattern Along Path effect to make the lines look painted on as if hand drawn by a tablet, this will help make the art look more organic and stylized.
If you want to animate, assuming only lines and filled shapes, you can import the svg vector file into blender for animation (it works but there is no online guide yet so learning how to do this is very hard at first, but I may make a guide in the future.)
hope there was something of interest here and best of luck!