I'd like to improve my game by learning quick counting skills. Tips?

Beginner counting techniques:

• In the opening: do not merely count but develop your positional judgment.
• In the middle game: estimate the territories in multiples of 5 and be very very aware of your state of thickness
• In the endgame I second the tip of counting in pairs and that's it. The technique, explained in DrStraw's pages, of taking an absolute number and then doing some accountancy strikes me as counterproductive. Count in pairs for yourself, count in pairs for the opponent, and substract.

Advanced counting techniques:

• Assume one sided sente endgame to be played out.
• Count the prisoners from the place they were taken.
• Remember the count at each location, to avoid recount for untouched locations.