I used to have one password for everything. Then I switched to random passwords like iD934jKb, one for each site, written down in a notebook. Then I decided on a system to have different secure passwords for each site but in a way I could reconstrue them using the name of the site, so that I didn't have to write them down anywhere. Then I changed that system because the system was too easy to figure out.

... I have a pretty secure system now. >.> Of course, even mentioning that I use a system like that compromises my password security. But hey, it's not "1234"...