Counting in your head.........how exactly?

Hey, I'm new and I'm trying to increase my hi/lo counting speed. How are you guys doing this exactly? Do you wait for all of the opening cards to be dealt and then count one hand at a time, by two's, each card at a time, what's the best way to do it? And are you always saying the RC in head so you don't forget it? And what do you do to prevent concentration lapses? I'd love to hear any other mental details about counting efficiently. Thanks.