My advice to you is to start sifting through obfuscated posts and figuring out how they work. After you have parsed 4 or 5 of them you should be able to start coming up with some of your own. Thats the joy of Obfuscation... figuring out how to do it well! There are lots of great examples here.
I've now updated this post with links to many great examples of obfuscation here in the monastery. Enjoy!

Okay, first... its my post, and it wouldn't be right to include my own work in my list of great examples, so here are my posted obfuscations:

• My first attempt at obfuscation
• My latest attempt (Haiku!)
• OneWay (with help from Tye)
• Pop pop pop

Now on to the really good stuff:

• There can be only one!    Erudil
• My 2 cents worth    Erudil
• Cool JAPH    Abigail
• Things are not what they seem like.    Abigail <! I miss having Abigail around. -->
• Punctuation JAPH    Chipmunk
• YAJAPH    Dominus
• A Re-Ordering JAPH    quidity
• holy cow    agoth
• Morse code    Anonymous Monk
• Tic tac toe and Tic Tac Chop    Jeff Connelly, turnstep, ...
• ZDog Obfuscation Part 2    zdog
• A first Obfuscation.    j.a.p.h.
• just another JAPH    sean
• My .signature.    MeatPopsicle

Also check out the tutorials from Japhy (japhy's Obfuscation Review) and autark (Unobfuscated obfuscated perl course).