Game Development

Idk if this will be fully relevant to game art, but I'll share what I normally do for art, more with a focus on references. My program of choice is Krita. Others have already brought up some good programs and resources

For Reference Poses and Images

• same.energy lets you search for a picture and displays what it thinks are similar images.
• PoseManiacs is a site that has a bunch of pre-posed 3D models in all sorts of poses that can be handy for getting down a specific gesture. With 3D models, I wouldn't really try to closely reference muscle shapes and such, since deforming a 3D model usually isn't accurate to a real human.
• If you're on Windows, I've used Design Doll in the past for, again, basic posing, like Pose Maniacs. It lets you customize and pose a humanoid mannequin
  • For Linux, I typically just use Blender with the MMD_tools addon to pose MMD models (usually from Genshin or HSR since they give those out for free) and work from there.
• SketchDaily is a site that will show you a set of images for a short amount of time with the idea that you try to draw the overall gesture of the image. It's a training tool for quick gesture drawing, which helps improve your overall confidence and ability to look at a reference and parse out whats most important.

and another thing, idk if you have a good eye for telling AI generated images from real ones, but I'd say try to avoid using AI as reference, since AI stuff can be inaccurate to real life, in both subtle, and not so subtle ways that could cause you some frustration down the line when learning. There have been times that I've sat down to do a study and got a bit into it before realizing it makes no sense compared to what I already knew and the image turned out to be AI Generated. Pinterest can have a lot of nice reference images too, but it really has become overrun with AI slop.