I'm not sure I feel qualified to give advice, but I certainly have lots of opinions I'm happy to share 😂
(fuckssake this got so long, my apologies. Or bone app the teeth, if it's useful LMAO)
1. The most important thing (at least for me) when drawing is having references; and that's the same for any NSFW art you want to make. You can look at art other people have done, study what other artists do (which has really helped me when it comes to expressions, learning how I want to draw parts of anatomy, etc)-- but at some point you... have to look at actual reference. Which can be you know, kind of uncomfortable for some people, and I get that! Not everyone is as comfortable staring at pornhub for 3 hours studying how to draw things as I am lol
The thing about nsfw is that it often involves bodies bending and moving and twisting in weird ways that you don't see in MOST sfw spaces. It's important to study how bodies move, and bend, and what happens to the curve of an ass no matter how bent over they are or how wide spread their legs are.
If you're one of those people who aren't comfortable looking at real people, there are some alternatives that can help you get there, anatomy wise. Try looking at wrestlers, gymnasts, and rock climbers, for example. BUT USE REFS. PLEASE.
2. The more into it you are, the more fun you'll have, and the better working on it will feel. I know everyone says that about everything but like. There's something so good about drawing what scratches that itch. Use your art powers for your own good. Make your own food.
3. STUDY FAT PEOPLE. DO IT. And I'm not just shaking a stick at you for inclusivity reasons (although I am also very gently doing that). Bodies have weight and squish; learning how fat works, where on the body weight rests-- these things are more apparent on fat people, or people with at least a little chub. Look at them. Learn from them. Go forth and draw weighty squish.
4. LAST THOUGHT: I just spent all that time talking about how nsfw art refs are ~oooh so different~ but I'm gonna tell you that at the end of the day drawing is drawing. You might have to practice different techniques for ref collection, and you might have to expand your knowledge of the human body-- but it's still just drawing. Don't get too worked up over the divide between sfw and nsfw art. (this is def something I wish I knew when I was younger-- it's not a completely new skill, you're just building what you already have.)