So you have the rule, you have the words, let's talk biological psychology for both men and women. It's different for men and women but it does have cross over for both genders. There is a general psychological "normal" associated with both male and female readers. Then you have the general psychology of transgender, gay, lesbian but let's start with your generic male and female because that's the biggest niche of the market for erotica writing (it shouldn't be but it is, although gay and lesbian erotica is on the rise, so is trans erotica and about damn time it is).
New to writing erotica? Don't know where to start? Think "love pole" is too frilly for you? Not quite the type to use "lick, suck and fuck" in your erotica as a descriptor (although those activities are quite fun aren't they). There are two categories of words you can pull from, the soft core and the hard core words. Depending on your comfort levels of course, personally.