Only after the last step, and not always. Will almost always decant if pitching into a lighter style beer, OR I'm using a floccing bastard like WLP005 etc that drops without any extra effort. Otherwise, you'll need a couple of days near zero for most yeasts to drop, longer for some non-floccer's. If have the time to let it drop out, I usually will, as that means I can do a vitality starter prior to pitch. BTW - Going from a 500ml to 2L, I'll put 200g DME into ~1.7L water, and boil until I'm left with 1.5L (or by weight 1.7kg). I'll then add the 500ml to that to get 2L.