There is the classic paper clip on the nipples but you can use clothespin too. What can words too, is to so short sessions (5-15 sec) of pinch on you little bud (clit) at the limit of pain/pleasure.
I would usualy keep my girl tease for as long as possible until her work is done, because she knows I would help her cum, it's quite effective to reduce stress and keep her focus on tast. So in that case it would be to get arousal for something you realy like and resist the urge to touch yourself. Set a timer (that you can't look at) for 15 min before your break ends so you can release all that tentions into multiple orgasms (where you are allowed to use all the "tools" at your disposal).
An other thing I use and it's very not sexual, it's just closing your eyes and focus on one thing in your mind, letting go of everything else, time will slow down and you will feel at peace, doing that for 5-10 min would feel like triple the time. And I even do that myself !
You goal should always be to enjoy yourself in those precious moment, it doesn't have to be with a dom or master. But I guess having a Dom you can rely on to give you that peace and quiet of mind would be a plus. I hope you find someone that will have the patience and care you seed.
Have a good time with yourself.
