Morning people, I am currently trying to create a custom skin for my game, based on a character from the Shingeki no Kyojin manga, (the female titan) however, all the tutorials I found are for GIMP, and I don't like that program, it's a true hassle for me to use it, I'm a digital artist and grew up drawing in photoshop and SAI, and I know skins can be created/edited (I dont know at this point anymore) using photoshop.
The thing is, I have to basically repaint/retexture the whole skin, I've found THIS beautiful tutorial that covers the last steps of saving and adapting a skin using photoshop, but I don't know how to open, transform it and paint it there.
What I'm asking is for a step by step guide (for dummies, please imagine that I'm a retard when explaining this because at this point I am SO confused with everything I cannot function anymore)
I don't know how far I can paint into the canvas, I don't know if I'm being clear with my question, but I'm pretty sure there's a limit for the "body shape" I can texture, ugh I hate not being able to explain myself... I don't know what will be "painting out of the lines", however, if you guys can give me a hand or ask me to explain myself better (which I currently cannot) let me know, I really want to do this, been wanting for a long time :/

Still needing help with this

To be honest, it's difficult to answer your question without some more info. What are your skill levels - i.e. are you looking for help with picking and using appropriate tools in Photoshop? Or are you happy with the actual painting process, but trying to figure out... I dunno, what to paint? Where to paint? Are you wondering about limitations in terms of what will work/look good with in-game rendering? Is it specific elements that you're unsure of, such as tattoos or scars or something like that?

In terms of contouring, you can do pretty much whatever you like, but bear in mind that you can't change the shape of the body and it has to look good from multiple angles - so stay away from anything which will look weird if you turn the sim around a bit and suddenly realise that the (huge knee/protruding horn/large belly/etc.) is flat.