(lazy) design student here, practice makes a lot and you have great sketch skills for posing. There are so many great tutorials by artists I love, for example Dave Rapoza, his paintings looks so real bc the awesome use of lighting.
But practice and follow the marks of artists you like makes your own style. On DeviantArt or youtube you could find a lot of great tutorials
@Skizoh your artstation is really neat, great work, Im so jealous of your style
Btw, two fanarts I made the past year
I suck at posing, I use mainly references.