This is just the basics, but anyone should be aware of it:
Budget: set it BEFORE you start gambling and stick to it.
Have a break from time to time, it is important to let your brain stop and consider.
Avoid drugs / drink as much as possible, they will make you loose some control innevitably.
Seek help if you feel you are no longer in control. Make a phone call to a friend or go out and speak with someone.
Anything else anyone can think of? Like... read this post before gambling?

I agree with what you said, all of these are important to a gambler if you want to be a healthy gambler and always enjoy it. Don't gamble if you're stressed, hot-headed, or out of the mood. We all know the outcome if you are forced to gamble in this situation.
Actually everything stated here is what I do. I often lose in gambling but that's okay with me because that money is really earmarked for my gambling habit and I enjoy it. Just don't gamble every day because you will surely become addicted if you lose control of yourself.