Well, I used to have trouble orgasming, a long time ago, although once we found a technique that worked and stuck to it I could have one every time. I don't know if I can give any specific tips, since everyone is different. The bondage and domination, though, it really worked for me, and once we started doing a lot of that it became easier and easier to orgasm in all different positions and with much less stimulation, and then finally to have multiple, many, many multiple orgasms. That's when he started the orgasm on command training, and it took only a week or so to get a pretty firm grasp of it. The important thing is for him to know when to give the command- you have to be right on the edge to start with. Then as it gets to be entrenched training you can work backwards, giving the command with less and less warm up. Successful practice (command always followed by orgasm) and avoiding any giving of the command when you are not ready is important.
The high point so far for me, was yesterday I came while Christmas shopping, with only a light touch and word from him. Twice. No one else was around and the clerk had gone in back.