To OP:
YAC seems to be kind of touchy. Also, there are many different ways to go with it. Probably the most important part of it is the play calling and the matchups. Nothing plays a bigger role in the production of your receiver than the OC. Of course, your QB also factors into this.
Some different routes you can take as a player (off the top of my head):
1. You can try to break the first tackle of the coverage via strength/carry/va's/sa's.
A. This route is difficult for a few reasons. Strength doesn't autogain for receivers, but does for everyone that will be guarding you. The WR trees have nothing to compliment it(so you will be a t a SP disadvantage). Investing many points in strength and carrying will cause your speed/agility to suffer. With this happening, it will be less likely that you are open. Not open=PD/no target/Interception.
2. You can try to elude defenders.(Juke, Spin, Head Fake combined with VA's)
A. These skills seem to not be very effective. They rely on being more agile then the defender combined with them not passing a vision check. Most guys you will face that have a clue on how to build players will have high vision, which render these skills useless at times. Also, Juke and Spin seem not to fire very often even at high levels(9+).
3. Getting open
A. The trick to this is being efficient at catching the ball while still being fast and shifty. This usually being the most efficient route seems to be the most used, hence the cookie cutter builds. Speed plays a huge role in this. Also, WRs don't usually catch in stride in GLB, so you need to get back up to speed quickly after you make the catch because the defenders will be closing in quickly. Speed is crucial here, and there are many things to compliment it for a WR. Agilty/RR/FS/QC
Whatever way you chose to go, the thing that can't be forgotten is catching the damn ball. For the OP: I'd worry about this first, un;ess you are happy with a 48% completion average.