I recommend peels and microdermabrasion the most, because exfoliation is so, so, so important. My top tip is to start with a series of peel or microdermabrasion and do them religiously for 6-10 weeks, and then maintain every week.  
Common Beauty Concerns
Facial Tips
Combination skin
Concocted my own scrub
How often should I get crystal clearing?
Who needs a facial?
Sunburn and microdermabrasion