Heading hasn't really been a problem for me so far, I've felt it to be quite balanced. It's the delivery I'm having problems with for the most part, but I welcome that after the ease of previous years.
The delivery of crosses is the one thing I'm actually managing to do really well with, I'm scoring an absolute ton of goals from headers in this year's game, in fact it's become my main source of goals.
I basically spent a little time in free training seeing what happened when you cross the ball from the advanced wing position (level with the penalty area and beyond) and seeing what happened when I crossed and used the direction stick in every possible position. You can get some brilliant whipped crosses in front of the defence, or if you manage to get to the byline you can cut the ball back beyond the keeper (if I remember correctly, attacking to the right hand side goal, on the right wing for example, I think if you cross while momentarily holding down/left on the L stick will see the ball being cut back to the penalty spot kind of area).
I also use really early crossing, from around the edge of the box and further out. Using L1 at the same time, you can see a different crossing animation and by doing it early you don't give defenders enough time to get back, while your strikers can actively run onto the the ball.
Here are a few headers I've scored, more often than not I've swung the cross in early.
YouTube - PES2013
Here is another video of a header I scored tonight, attacking left to right I pulled the L stick pretty much diagonally down and right to cut the ball back.
YouTube - PES2013
The variety of crosses you can play in this is stunning, and the best advice I'd give is to try crossing in situations where you wouldn't normally attempt it. For example, one goal I scored that I didn't get a video of, was where I held L1 and 'crossed' the ball from halfway in the opponent's half, near central. It basically served as a long ball into the box and caused chaos, before ending in a goal.
As for types of headers, I don't really believe you can deliberately pull those off, it's entirely down to the body position of your player when the ball hits his head. That said, you can pull off lower headers by tapping shoot so it barely registers on the power bar, or use R2 like a controlled shot.
But if there is one thing I'd say is proving to be most successful with scoring headers, it's crossing early.