Read my sig line, save up $6k and replicate my every move.
Just kidding. Avoid the CAI, I've done it and can tell you it will disappoint you. What direction do you want to take your truck? Off road? Street only? Combination of the two? What kind of budget are you working with?
A few cheap mods I've done that I'd do again any day:
Total Chaos steering bushings $35 (installed myself)
Diff breather mod $20 (installed myself, might not need if you don't off road)
Sprayed my bed rail caps, door moldings and grille with Rustoleum bed liner $70 total. This works especially well on black trucks.
Window tint $120
Removed mud flaps and fender trim for free
Here is a link to my rattle can madness in case you are interested.
Drunk's side molding remedy
I used the same exact technique on my grille, so far so good.