i use a combo of studio finish spf15 (in the pot), select cover (tube) and touch-up stick. i'm NC20. i use the touch-up stick in a lighter shade (NC15) around my eyes to brighten them, and i usually draw a line directly along and under my brows smudging downward to act as a soft highlight and to define the shape of them.. i use the studio finish on general discoloration, especially on cheeks and t-zone, because it's thick and covers nicely.. and lastly select cover in a corrective shade if i have any blemishes. i noticed that the pencil concealer is good for precision around the eyes and brows, the studio finish is good for heavier coverage, and the select cover is excellent for covering pimples or blemishes because it's thin and can easily cover something like that without looking like it's just sitting on top of it. studio finish concealer is also really nice to pat onto the lips to "erase" them or to neutralize a lipcolor a little bit.
so, those are the three concealers i use. haha.