Very helpful ideas on here.
Here's another one:
Make a standard password that you always use. Make it tough to crack (Some caps letters and numbers etc.) Then for each site, use that password but add onto it add the third & fourth letter of the site. for example, lets say your password is: starr1978, then for facebook it would be starr1978ce.
I don't do this but someone told me to do it and it seems like a good idea because its easy to remember