Step 1. Pick a phrase you wont forget
Step 2. Haxor it up however you want
I have a set of rules that I follow for every password. Try to keep all your passwords consistent otherwise you will have problems remembering. You don's have to have really long passwords like the examples just make sure that its not too short.
Step 3. Salt it for multiple sites
Step 4. Rotate it
Don't use the same password for long periods of time. Change it every so often.
Also, if you need to write your password change that caps for every letter. At least if they find it, they have a hard time deciphering or maybe even give up.