Is there any new guides on this in the past couple seasons?
What are ya'll doing, what is working, what is not?
What are ya'll doing, what is working, what is not?

Seriously though. What I did was take the time to do 2 things. #1, map out the formations against each other (kickoff vs kick return and punt vs punt return). Take note of how the positions line up... and then, #2, watch replays of kickoffs and punts. From this you'll see how certain things show up and give you clues. For example; If you see a gunner (outside player) cause his opposite to "fall down" (as if pancaked... but he isn't, really)... then you'd eventually figure out the reason the dot fell down was because his agility wasn't high enough to face his opponent... and he fell while trying to block his more nimble opponent (see this happen many times). Or, you'll see someone exploit "gaps" in the defensive line (on kickoffs) and get downfield to make good and quick tackles. This happens when you get good speed and agility enough to shoot those gaps you saw when you faced the formations against each other. Lastly, why back wedge and back blockers fail to engage blocks before the returner dashes by them. Reason? Not enough speed and agility to beat the returner to the blocks. Causes the end of many a good return. 