Kegals, edging, etc work well.
A lot of ejaculation is mental. I've tried a lot of the whole 'think about something else' tactic and it only seems to work for a little while. At first it seems to work, but then while your mind is off somewhere else, your dick is doing its own thing and then all of a sudden SPLAT, game over.
The best thing I've figured out so far may sound odd. The only way I can describe is is that you have to be in a 'conversation' with your man parts. Don't focus on the way she's moaning or touching you, don't focus on the way your dick feels in her, focus on what is happening inside your abdomen right behind your dick.
This takes practice. When you masturbate you can feel the orgasm build in stages. Everyone is different, but knowing your own stages from tingling in the balls to that fiery sensation on the head to the involuntary flexing of the PC muscle. With a bit of practice, I find that if I focus my mind on this, I can voluntarily control these stages to an extent. I practice without adult entertainment initially, then when I think I can focus my mind I add adult entertainment. I will notice that it is more difficult to stay focused on self control, especially if it's good adult entertainment rofl. After I have 'warmed' my mind up, I can masturbate indefinitely while staring at the hottest adult entertainment. It becomes no longer a question of 'how long can I last?' but 'how long do I want to last?' The key is to have your mind 'in' your dick/abdomen, not in the adult entertainment/stimulation.
Girls are a whole new level of stimulation, so mental control needed even more. I haven't gotten any since I've been trying this technique, I'll let you know how it goes.