One important thing for this post is the distinction between kinks and fetishes. A fetish is a strictly defined term, and in terms of sex means something without which someone cannot have sex. A kink on the other hand is simply something which can enhance the experience or enjoyment of sex. I have many, many kinks, but no true fetishes.
Now as to my own experiences, my first experience of rough sex, sadomasochism, was also the first time I actually had sex. That one I have already talked about, so this is more for the others.
Mainly in alternative sex, as it is sometimes described, I tend to take a dominant role. It can

I could barely move afterwards. Being locked with your wrists to your ankles for eight hours of writhing and struggling takes its toll on your joints. I had marks around my wrists and ankles for weeks afterwards.
Of course as I said I have been very much on the other side before, I have had people acting as my pets for days, following every order, surrendering everything in the way of choice to me for a time and taking punishment if they disobey. This is why I am looking forward to my trip to Ireland, it has been a long time since I have been able to play with someone with that level of submission. I have various toys along those lines, a simple whip which I have never used. It is more a prop than anything else. A cane which is particularly well-made, with a nice weight, and leaves good solid welts when correctly applied to the body. Carefully blunted knives which can prick and give the illusion of danger, but are incapable of actually cutting.
Safety is actually important in this sort of sex though. Safe words are used in case things go too far, something I am careful to establish with any partner who may be partaking in risky activities with me. I have spare keys for any restraints I have, and a small set of lockpicks just in case those go missing.
Definitely looking forward to Ireland though, where I can actually put this sort of thing to its full use again. I may not want to indulge every time, but every now and then it is an urge which I want to have a chance to explore.