Obviously, not all women are the same, so take these with a grain of salt and enjoy.
1. Being honest about needs:
"Be honest with yourself as to what you like and need. Was with a guy who NEEDED to finish by hand, but desperately didn't want it to be that way. He would just keep going until it started to hurt me, and then feel ashamed. I have no problem with you taking matters into your own hands while I help in other ways!" — Cohult
2. Maintaining:
"When I tell them to keep going and I like it, and they start to speed up or change their tempo. I liked it the way it was before." — Zoeyz93
3. Being too serious:
"Not being willing to laugh about things that go wrong." — becauseimcountolaf
4. Communicating:
"Lack of communication. You could avoid all the mistakes listed here and be doing it completely wrong for your partner. Not all women want the same thing. Talk to your partner." — Mr_frumpish
5. Speeding up:
"When we say 'don't stop,' DON'T START SPEEDING UP! Keep doing EXACTLY what you're doing." — strawberrychel
6. Not cuddling:
"Lack of post-sex snuggle. I hate abrupt endings." — Stabfacenotback
7. Cutting your nails:
"Please learn how to use your fingers. Cut your nails. Don't try to rub a hole in my clit. Don't poke. It hurts!" — Dolliiy
8. Doing the head push:
"The head push. We will go down on you when we are ready and willing." — Frtyto
9. Not being clean:
"Not taking a minute to wash up first." — coffeeblossom
10. Losing the rhythm:
"Lose rhythm! My GOD, how often it happened that I was on the edge, and he changed the rhythm and I just couldn't come anymore after that!" — Vlinder_88
11. Dick-slapping:
"Don't slap my face with your dick. I don't know why guys do this, but stop." — wickedwix
12. Moving in a circle:
"When he is on top and starts moving his hips in a circle. Man, just go up and down!" — wildcat777786
13. And most importantly, skipping foreplay:
"The number of men who think good sex is them pumping away, without any kind of foreplay involved, then are surprised when we tell them we didn’t have an orgasm is troubling. Or the 'foreplay' involves jabbing at our nether regions with their fingers like they’re trying to stuff something back inside of a box." — deadsharkeyes