IME this can be the best position or the absolute worst depending on the skills of the man you’re with, and how bothered they are about your enjoyment vs theirs.
At the wrong angle, especially with a well endowed partner, it can really hurt, especially if they think that sex is just slamming their penis in and out of you as hard and fast as humanly possible (ick).
With the right angle it can be incredible because of the g-zone stimulation. When I was younger, I didn’t think I had a g spot, I’d never felt it and sex from behind wasnt great.
Then in my 30s I went hunting for my g spot while enjoying some alone time with a small bullet vibrator and boy did I find it! Except it’s not a spot, it’s several and on the front wall and the back.
When you first start exploring this a) you may not find it and b) it might not feel great. If you ever get a slightly queasy feeling during sex from behind, that’s probably what it is.
Most important thing is to be very very aroused and relaxed. Mine only really starts working after a few orgasms and when I’m really in the mood. Experiment on your own and find out what feels best (tapping, hooking and pulling at it, etc). It can take some pretty firm stimulation to get anywhere especially at first - apparently glass or metal curved dildos are the best way to find it and get the necessary stimulation. I don’t need that fortunately.
In terms of any position where your partner is behind you, you need to take advantage of the curve of your vagina so that the penis is stimulating the right point for you. If it’s on the front wall, on your knees with your back arched or both upright works well. If it’s the back wall it’s trickier, but lying flat on your front works well.
If you’re with a partner you trust and feel very comfortable with, one of the best ways to experiment with this position is to ask them to kneel behind you and stay still (very important!), back up on to them and then experiment with moving around on them. If I’m having sex in this position generally, the movement is more in and out, but if I’m taking the lead to make it as enjoyable as I can for me, I find moving my hips side to side and grinding much more effective - I can handle much deeper penetration if I’m in charge and know that he isn’t going to start slamming me in the cervix!
Yikes - that was more detail than I intended 😂