This node is in memory of Where do I come when I masturbate?1.

Note 1: This node came about as a result of the aforementioned (now ex-) node, and the unexpected responses I received about it. It appears many people are having bad orgasms for the wrong reasons.

Note 2: I will only be dealing with a small aspect of orgasm-improvement here. I will not touch topics such as solutions for impotence, male multiple orgasms and the various types of female orgasm. Also, this node is not about having better sex or giving your partner better orgasms. It is about making YOUR orgasms better.

With that out of the way...
All sexologists agree: the main sexual organ is the brain. It is here that sexual excitation begins (arousal), and it plays an incredible role in all aspects of the sexual encounter 2. This is true for both men and women. Thus, it is on the mental part of the encounter that I will focus most of my attention on in this node. Almost all information is relevant to both sexes.

So, how DO we improve our orgasms?

By far the most important aspect of the orgasm. If you are thinking about something else, the orgasm will be less powerful, and at any rate, much less enjoyable. There is no trick here. You have to make sure you are not thinking about your income tax form or HIS income tax form, or what you have to remember to do in the office tomorrow, or about the Spice Girls reunion, or any of a myriad other things.
Also, and this applies mostly to males, you have to focus on the enjoyment, and not where it's going to go. If you masturbate, make sure you have planned ahead where to come3, and make sure it's somewhere that you won't have to think about when ejaculating. So, catching it in a towel or a wad of toilet paper is right out.
Being in focus is strongly linked to
When you orgasm, to make the most out of it, you have to completely let go. At that moment, you don't care if you look like a squirrel or if your city is getting bombed. All your existence is focused in the orgasm. With masturbation, trust is not really an issue. But, with a partner, you HAVE to trust them to be able to fully let go. Many (most) people can come with people they do not completely trust, but it can never be as good. You will never be able to give yourself up to someone completely unless you have absolute faith in them.
Being in the mood
Romance plays a role in this for couples, but it's also important to keep it in mind when alone. I have a friend who told me masturbating had become a burden for him. He woke up in the night, HAD to masturbate, and did it to get it over with. This is NOT good for the orgasm.
For couples, I'm not just talking about candles4 and sunsets (though they are good). Just do whatever YOU need to get you in the mood for sex, be it kissing or cross-dressing or watching Sleepless in Seattle5. The more you want it, the better it will be.
Delayed pleasure
The general rule is: the longer it takes, the stronger the orgasm will be. This is split up into two categories:
  1. TBO (time between orgasms) and
  2. TTO (time to orgasm).
Remember your first orgasm? I remember mine. It was so overpowering I nearly drowned. (True story). A part of the reason is that I hadn't come for 13 years. I also tried this a few years back; I didn't come for a month. It was powerful when I finally did. It's tough to incorporate this tip into your love life, as you probably won't want to abstain for a month, but keep it in mind. TTO is very important, though. Stemming from both psychological and physiological factors, which I will not go into (I am simply not educated enough in orgasm physiology in men or women to write an in depth explanation), quick orgasms will always be shorter and less satisfying. This is the general case. There may, of course, be good fast orgasms, but they are few and far between. In general, men and women tend to sin in this category often when masturbating. Thus the orgasms are not as strong as they could be. (Think: if you're not masturbating to get the best orgasm possible, why bother at all?)
Being open with your partner means letting him know what you like. Some partners are more attentive, others less. It's important to realize that each person has their own erogenous zones. If your partner knows your zones well, you will have better sex, and better orgasms, because he will learn how to optimize your orgasms.
Strange as it may sound, this also applies to masturbation. Be honest with yourself about what you like, and try different things. For example, some women may enjoy rubbing the clitoris while at the same time using a vibrator, while others will find the vibrator a distraction. Find out what YOU like.
Stop & Go
I don't want to get into the realm of the physical too much, but I think this "technique" deserves a mention. It is related to delaying your orgasm, but is not quite the same thing. Stop & Go involves approaching orgasm, and stopping (or slowing down) before reaching it, then building up again, and so forth. This is done several times. The closer you can get to the orgasm without it happening, the better. Then, when you finally do reach it, it can be several times stronger. Needless to say, this tip is both for partners and Hand solo6.

All that said and done, I must stress that orgasms are very nice, but everything around them (foreplay, sex, etc.) is as important, if not more. It is much better to have good sex without an orgasm than bad sex with an orgasm.

1 See All noders are created equal, but some are more equal than others for notes on the demise of Where do I come when I masturbate?. Hmmm.... update: see dem bones for notes on the demise of All noders are created equal, but some are more equal than others/
2 I am using the term sexual encounter in the widest sense here; it could also include masturbation.
3 Yes, that's how it's spelled. See come vs. cum.
4 Candlelight, not hot wax. (Although who am I to say?)
5 I am NOT condoning watching "Sleepless in Seattle".
6 I HAD to put that one in, for all the Star Wars fans.