Loud praise/ Quiet criticism

I would hope most of us use loud and often public praise and quiet private criticism in all our endeavours, it seems to me the most effective technique.
Unfortunately with limited practice times, pace and logistic limitations in youth football sometimes you have no choice but to publicly correct. When doing so I always try ( not 100% successful) to keep it low tone and "sandwich" the correction between 2 positives.

Ex: Head on wrong side on seal block:
Joey you started off with a perfect stance which is great but on the seal block of the linebacker you had your head on the inside which makes it real easy for him to slide off and do what? (he replies make the tackle) Which is what we dont want to have happen. I know you can make that block Joey you are a good blocker.

If I ever forget to use the sandwich method I try and get a public praise moment in with that player before the end of practice about SOMETHING even if it is very minor.
We correct most everything in practice but in games we stay very very positive and any corrections there are done as positively and quietly as humanly possible.

Every kid is different, each has to be reached in his own way. It's good to have an overall philosophy and base approach when dealing with issues like this, but on occaision you have to go outside the box. One ADD type player of mine, the best way to reach him is to sit him down on a big blocking dummy by himself and have him watch us do reps. I prasie the heck out of his replacement, his replacement can do no wrong. After 10 minutes of this "torture" my ADD kid seems to be significantly more attentive. Just 1 example.