Although this is not really a technique for masturbating, it is some ideas of what I do when I cum. I love eating my own cum and of course always get my wife to kiss me after I cum in her mouth so she can give some of it back to me. But one of my favorite things to do is masturbate and cum in one of the small medicine cups. I then place it in the freezer until my next masturbation session at which time I will cum in the cup again then freeze again. Before long I have a "cum ice cube" which I then place in my mouth and let it slowly melt, giving me a "slow-release cum snack".
The other option I have done before is to use a taller container, such as a tall narrow medicine bottle and I cum in it. After the second or third masturbation session I then place a popcicle stick in it and continue cumming and freezing until the bottle is full. After it is full I dip the bottle in warm water, careful not to let the water go over the top of the bottle. I leave it just long enough that the "cum on a stick" slides out and then enjoy the treat. This option does take longer, but then the treat of eating my cum also last longer. The coolest experience I had with this option was once in the summer when I was outside wearing only a pair of gym shorts (the short kind) and eating my "cum on a stick" when my female neighbor came out and was talking to me. The whole time we were talking I was eating my own cum in front of her. Of course after she left I had to immediately go inside and masturbate!