As we mentioned back here, most people pick too-easy passwords for the many places on Ye Olde Internet where they need one. It seems to me that this will often be the case when you're trying to come up with one that you can remember. Yes, it's possible to think of one that would be hard for a person (or of greater threat, a computer program) to guess…but you should also use different passwords on every or nearly every site.
All of that made me decide I should, first of all, forget about trying to remember passwords. I just now use a different one for every place I need one and I don't try to keep them all in my mind. I keep them in Roboform, which is a fine program that stores your passwords, credit card info and other data. They have a pay version and a free version…and frankly, the free one isn't much good except for testing it out on your system and, if you like it, upgrading to the one that costs cash. But even then, it's only thirty bucks.
I've directed my Roboform to store all its sensitive data on a flash drive I keep plugged into a USB port. I can take it out of the computer and carry it with me…and when I do, my passwords and such aren't even on my computer. If you do this, it might be a good idea to back the flash drive up to something else…which I do.
So what about the passwords? I just use gibberish. You can generate your own like this: gfuir9u or vrfe5ori or cf984Nfd but it's easier to use GRC's Ultra High Security Password Generator. It's free and you can add it to your browser toolbar so you can access it immediately whenever you need a new password. If a site requires one of 8-12 letters, I just zip over to the U.H.S.P.G. and copy 8-12 letters off whatever they've generated for me. Couldn't be easier…or as I like to think of it, couldn't be 1jokwdT!