I use a simple little system, where I have an easy to remember, but long (16+ character), and then tag on two or three characters that are unique to the URL or application.
So:
myreallylongpassword!xim
Studies have shown that we make passwords harder than they need to be to remember, but easy to break by brute force.
myreallylongpassword!xim > p4s$w0rD
String four or so words together, randomly, or just a short sentence. Add special character. Done.