I will try to start this off:
I count carbs every day at every meal. I do this in order to calculate my bolus insulin dosage. It works very well for me, as I have lowered my A1c from 11.3% to 6.9% in a four (4) month period.
I learned to do this from doing research on the internet. Below is a link and I hope it helps you as well.
Carb Counting 101