This is going to sound ridiculous at first, but bear with me.
Draw some smut.
SERIOUSLY.
A. It’s fun. You don’t have to show it to anyone (unless you want to) and it’s a good way to blow off steam. When I can’t work on my main projects any more, I switch to working on my erotic mini comic. It’s getting something done without it being a huge commitment and when I’m done with it, I’m ready to get back to work!
B. Don’t see anything you like in the vast sea of internet porn? Draw what -you- think is hot! Like I said, you don’t have to show it to anyone. Guaranteed someone else will find it hot too. Hell, there might even be a market for it!
C. As the title implies, it’s great for practicing character interaction. As a comic artist, it’s tempting to just switch back and forth between your characters and imply that they’re in the same room and interacting. Drawing smut forces you to draw the characters’ bodies actually interacting! It makes you think about where the arms and legs would go, where the hands go, what the hands are doing, the size differences of your characters, etc.
D. Did I mention it helps with your anatomy? I’ve gotten so much better at free-handing hands and feet just because I’ve done some sexy doodles. It also helps with understanding and drawing different body types; you don’t have to just draw the stereotypical beefcake banging the Barbie doll. (of course, you totally can if you want to!) You draw what you want to draw, what you find hot. (see point B)
E. You never know when you’re going to need to draw a dick and they are surprisingly tricky to master. You’d think it’s just a tube shape, but no! And don’t even get me started on boobs!
F. You get a wider understanding of composition, particularly of love scenes. The last thing you want is for a sex scene to look like two dolls being pressed together. Even if the sex is supposed to be incredibly awkward, there is a certain poetry to that composition. Sex can be rough, gentle, romantic, awkward, angry, clumsy, giggly, etc. At the end of the day, it’s just two bodies, intertwined.
Give it a try! You might even learn something!