New here also; been doing self bondage a long time (I'm 81 now, but the only reason I look this way is because I spent 4 years in Isla Vista during the 60's....
I'm male, straight, but occasionally fantasize. Now to the important conversation - how to have effective bondage sessions without killing yourself. Some new products have become available that make this possible;
1. the first was the KitchenSafe which has been rock solid for me. I attach keys to a piece of twine under the lid, so I can extract them after the timer is off. The batteries last a long time, but it is still best to replace them, especially if the LCD starts dimming - if they go out during a session, the box will not unlock.
2. I'm experimenting with the new time locks available on Amazon. So far so good - I use two in a row as a failsafe (plus padlocks/kitchen safe as well.
3. I do not use metal handcuffs, since they can cut off circulation easily., IMO. Rather leather cuffs, there are a number of vendors I have learned to trust over the years; e.g. Extrreme Restraints, the Sub-Shop, etc. Also a few successful DIY for specific projects.
Self-Bondage to me is (at my age) not so much for sex as for forced meditation. I sometimes use a posture collar with a polyurethane pipe (3/4 as I remember) as as spreader, separating the front ring from the handcuffs, with a chain running through it, cut to fit so there is very little play. That prevents my hands from touching my head during the session. There are some great gags and blindfolds on Etsy, and I use a motorcycle helmet (with faceplate removed ) to give a comfortable sense of sensual deprivation. I use two kitchen safes in that scenario in the same room (where I am seated in a comfortable gaming chair), and do not bind my feet - there is a third backup in the kitchen, just in case..... But a pain to get to if blindfolded and bound - so far I've never had to use it.
I also set Alexa to play sounds during the session, with reminders on the half hour (usually two hour sessions)
I guess my main advice is never, never, ever go cheap. Always buy the best quality gear, and research before you buy ( although you do have to take chances - it is often very difficult or impossible to return a BDSM item, even with reputable craftsman, for obvious reasons.
You probably know this already, but just in case someone else comes across this thread ....
(I had to deal with guilt for years - how can one possibly be attracted to bondage considering Auschwitz? - until I married a wonderful woman long ago who guided me to sanity. with a great sense of humor and understanding of the existential absurdity of the human condition I wish she were still available .....