Honestly the biggest thing to remember to to write what you know. It sounds simple but applying it is a wonderful thing. It really can change how something reads. Let me give a quick example. I'm a lesbian, so right there we know my straight sex scenes are nowhere near as together as my girl on girl scenes. I asked myself why that was, one day. My partner asked, "what's the difference?" Then it dawned on me that I knew next to nothing about having sex with men. It was stupidly simple.
So write what you know. If you like girls with big butts, write it! Guys with massive packages? Doooo ittt! Even kinks, if you know it, own it! Odds are, someone else wants to read it.