You should know that these tricks are old, and any decent password cracker worth it's salt tries these combinations too. Adding the four extra characters to the end is about the only thing.

Use something like keepass, with a decently strong master password (the scheme you describe above is adequately strong, unless you take into account someone who knows you IRL and wants to decrypt your password library) and then use really long, high-entropy, complex passwords for everything.

Never re-use passwords between multiple sites unless they're absolutely meaningless (I have a simple password that's composed of two dictionary words and two digits that I use for drive-by registrations on sites I'll likely never visit again).

Another option: Jesus Christ, Use a Password Manager Already

I USED to do a variation of this, but I would not recommend it now since many password crackers take these keyboard patterns into consideration.  Just use a password manager, like Lastpass.  Strongly consider using dual-factor authentication for Lastpass, such as with a Yubikey (look it up, very easy to use).  Be aware that a password manager is only as strong as its weakest point, which for Lastpass is the e-mail address you use for the account (which serves as the password recovery mechanism).  So consider using an e-mail that permits two-factor authentication (like gmail) and use a very strong memorized password for that e-mail with as many "random" characters as possible.  And be sure not to store the e-mail in Lastpass!!!  But with this system, the only two passwords you'll need to remember are your passwords for Lastpass and your e-mail account -- make sure they're not the same.  For every other account you have, you can then use 16+ character random passwords with special characters that no one can crack.