Eyebrows - get them threaded/waxed and tinted if needed. A good set of eyebrows really helps a face. Not that expensive either.
Eyelashes - having them tinted looks really nice, and saves putting on mascara all the time.
Some sort of BB cream, that helps even out your face but doesn't look like you are wearing thick foundation. I use Garnier skin active BB cream.
Clothes - find your style. Depends on your size. A nice pair of fitted jeans and tshirt, with ankle boots. And a scarf thrown round your neck.
Hair - have you had a haircut recently? Taking the ends off of hair and shaping round the face can really make a difference.
Underwear - get a nice matching set of bra and knicker.
To me, I feel prettier if I'm wearing nice underwear with shaved armpits and legs.