I'm going to share my own advice, but everyone else should feel free to share theirs as well. I've experimented plenty over the years and have found certain things that have really increased the pleasure I get from masturbating. I'll list them in order of "biggest difference" to "least-big difference."
1. Prostate stimulation
Like most guys (I imagine) I was pretty leery of trying this, but, holy hell, I can't stress how much of a difference it's made. The prostate has as many nerve endings as the penis and can have its own version of an orgasm that feels entirely different than a regular orgasm: more like a full-body ecstasy type feeling, and it can last for minutes if you concentrate hard enough. Even without the P-Orgasm, prostate stimulation will increase the intensity of your regular orgasms by a ton because it plays such a huge role in that already.
After getting into it I've tried various massagers and the best I've found is this one:
https://www.amazon.com/gp/product/B07GKXF8YR/ (not affiliated with the company/manufacturer in any way). It's small enough that it's easy to forget it's even in, and unlike most it has a "wave motion" that's basically like a finger putting pressure on it. This feels very different than just vibration, and both can be extremely pleasurable. I've also found that, of all the various things I've tried to improve masturbation, this is the thing that doesn't seem to "get old" or lose much of its effect. Of course, your 100th time probably won't be as good as your first several, but that's true of anything regarding sex.
2. Fleshlights
After using these it's hard going back to my hand and sometimes these can feel even better than a real pussy. The first few times using this was probably the most intense orgasm I'd ever had, and while that effect has lessened with time, I still find them much better than the alternative. The different textures are fun to play with/mix up too (for those who have them: don't forget to try the OTHER end occasionally!).
3. Edging
Basically the process of bringing yourself close to orgasm but holding back. The longer you do this, the more intense the eventual orgasm will be. It takes patience and discipline, but I've "edged" for hours before and it does make the orgasm a lot better. The effectiveness does decrease the more you do it, though.
4. Cannabis
Pretty self explanatory. Weed makes most everything better. I've found that I especially love close-up/POV porn when I'm high, like cowgirl with a camera right up on a big, beautiful ass is just heavenly. Something about the tactile nature of everything is enhanced. Cannabis also messes with your sense of time so that when you orgasm not only does it feel more intense, but it seems to last much longer. These effects do lessen considerably the more you do it, though. I still enjoy masturbation (and sex!) more when high, but not as much as I used to when it was all really new.
5. Nipple stimulation
This will probably be hit-or-miss with most guys, but I have found that my nipples are sensitive enough to where I can rub them and easily get an erection and even induce those little "spasms." One great use I've found for this is that if you only do nipple stimulation for a long session you can really build up your sensitivity so that when you finally do start actually stimulating your penis (via hand or toy) it will feel much more intense.
6. Longer sessions
Most of the above tools work better when you're willing to take your time rather than just rubbing one out as fast as possible. This is good because it means more time to watch more porn! I've found the "sweet spot" (for me) is 2-3 hours. I basically look at it as another form of entertainment like watching a movie.
7. Frequency of sessions
This will also be different for all guys, but how often you masturbate will have a huge impact on how good it all feels. I've found I can easily masturbate twice a day, but at that frequency each session is less pleasurable the orgasm less intense. I've found the sweet spot for me is actually about 3-5 times a week. At that frequency every session is really pleasurable the whole way through. I've tried going longer and find that it's really diminishing returns after that. Though I recently went 11 days because an ice storm knocked out the electricity for that long. When I came back I was really too sensitive to enjoy a long session, but I will say the first few sessions after that were more intense than usual. Even so I wouldn't want to wait that long just for the added intensity, but YMMV.
