If you're having problems with engorgement between feeds double sided feeding will actually only make it worse. If you're wanting to encourage your milk supply down then I'd just stick to one side. If your LO happens to come off still looking for more you can offer the second, following the cues is the important thing, but if he's perfectly happy after the 1st then stop there.
Breast compressions are a really handy way of squeezing out those last few drops of hind milk. See here for how:
http://babywhispererforums.com/index.php?topic=88759.0As to how to tell if your baby's nursing (taken from Jack Newman again)
1. Baby's nursing is characteristic. A baby who is obtaining good amounts of milk at the breast sucks in a very characteristic way. When a baby is getting milk (he is not getting milk just because he has the breast in his mouth and is making sucking movements), you will see a pause at the point of his chin after he opens to the maximum and before he closes his mouth, so that one suck is (open mouth wide-->pause-->close mouth). If you wish to demonstrate this to yourself, put your index or other finger in your mouth and suck as if you were sucking on a straw. As you draw in, your chin drops and stays down as long as you are drawing in. When you stop drawing in, your chin comes back up. This pause that is visible at the baby's chin represents a mouthful of milk when the baby does it at the breast. The
longer the pause, the more the baby got. Once you know about the pause you can cut through so much of the nonsense breastfeeding mothers are being told— like feed the baby twenty minutes on each side. A baby who does this type of sucking (with the pauses) for twenty minutes straight might not even take the second side. A baby who nibbles (doesn't drink) for 20 hours will come off the breast hungry.
on the intro page to the brest compression video you'll also see pause in chin videos listed, these illustrate the way a baby looks when they're actually swallowing.
