Thank you!! I love questions like this... This has a couple parts to it depending on what part of posing you're talking about but I'll just cover what I can think of.

Most obvious is probably anatomy, knowing how and where to break it helps a lot. Admittedly I still have a long way to go w anatomy, esp anatomical perspective, but you can do a lot with just enough. I really really like hitting the extremes, like limbs locked at their fullest extent vs totally limp. I also enjoy throwing in torso and limb twists wherever I can. I super recommend the Morpho series to have on hand when doing anything. The books are relatively cheap and convenient to carry around, but most of them are easy to find PDFS of online. Simplified forms and the base anatomy for artists are the two must haves, seconded by the fat & muscle bodied ones. The others are all nice-to-haves but I wouldnt buy them if you're tight on cash.

Another tip is to look at complicated stuff as just a bunch of simpler stuff combined. I usually start w something I want to highlight, the groin, an expression, the tension or force of an action, and build the rest around it. Sometimes I'll use negative space and try and frame something else like a face with it. Other times I just kinda start with a motion, in most cases I start with the spine, bc whatever that's doing is gonna inform the rest of the body. You can build tension by having, say, 2/4 limbs kinda ragdolling, following the line of action of the spine, and the other two fighting against that action, being the deliberate focus of the person's expended energy, if that makes sense? Thinking of parts of a pose as their own shapes helps a lot. Like a leg bent at the knee isn't a single long limb out of the body but a triangle kind of thing. You build complication by mixing those shapes and contrasting them to one another.

Other than that uhh if you watch any live porn reference your favorite stuff. 3D porn too. Things that are cinematic help a lot. I don't even like vanilla overwatch porn but a lot of that stuff has good posing and composition in it...

That's all I can think of right now! Some keywords for further googling: Line of Action, line of gravity, Contrapposto, negative space. There's probably more but baby needs a nap.