Hi Mariano, personally I've most often found Near Post aiming (from both left and right) to be most effective, but you really need the right kinds if players doing the right tasks. If I have enough left and right footed players, I will try for inswinging corners (right-side corner taker is left-footed and vice versa).
These are the attributes that I look for when choosing tasks:
Attack Near Post: Heading, Jumping and Strength. This player is generally the best header of the side, and ideally tall also.
Attack Far Post: Finishing, Composure. This player won't really see the ball unless it misses everyone, but needs to tuck away half chances.
Challenge GK: Tallest player, strength. He must be your tallest player to obstruct the GK's vision, ideally very strong as well.
Near post flick on: Heading, jumping, agility, finishing. This person will generally finish anything that goes to the near post, but needs to be capable in the air as well.
Lurk Outside Area: Long Shots, Passing, Creativity, Decisions, Flair. The Lurker must be clever enough to decide if possession needs to be recycled after a corner or if a shot is on. He needs particularly good passing and long shots to take advantage of whatever comes.
Attack Ball From Deep: Heading, Strength, Finishing. One of the better headers in the side, ideally with good finishing.
Stand On Far Post: Finishing, Composure. Similar to the far post attacker, this one needs to be able to quickly finish half chances that make their way to the back post.
I set two players (usually defenders) to stay back and whoever is left to go forward.
I must say though, that if your corner taker is rubbish, then you're probably best to go with short corners with your best crosser near the taker.
I'm sure there are many other good setups that you can use, I've just found near post to be the best for me.
Good luck with it