I'm doing a lot of sorting at the moment, not that I'd say I have any tips. I bought a 15kg lot on adverts.ie a couple of weeks ago, first time I've ever done that, it was just too good a deal to refuse. So far I've cleaned and sorted nearly all the bricks, panels and plates, but still have to do windows, doors, tiles, vehicle parts, Technic parts, baseplates, weird oversized parts and "miscellaneous". I used up every empty container in the house sorting it into those broad categories at the start before cleaning. Also yet to be sorted: a few parts that will need extra cleaning work with an old toothbrush to get glitter and chocolate off them. Not looking forward to that.
Cleaning it is annoying, mainly because it takes so long to dry. I put everything into a big box, run it under the bath tap with a bit of washing up liquid, slosh it around, drain it (with difficulty) and rinse. Then I've got two towels laid out on the floor and I just spread it all out on those. After two days of letting it air dry I start sorting. It takes me about 2-3 hours to thoroughly sort two towels worth of Lego by type. Most of it's going into ziplock bags that I've saved from past Bricklink orders, although I'm now almost out of them and only have the really tiny ones. I go around by type, starting with the large pieces that are easier to pick out. I clear a space to put piles and do all the 1x2x5s, 1x1x5s, 1x16s down to anything over 1x8 so I've got about 6 piles, then when I've got all of them I bag them and start on another set of types e.g. 2x10 down to 2x2. I think trying to sort all types at once would just mean you have too many open bags on the go at once.
Inevitably I find ones I've missed though and have to go back. For some reason I seem to have
1x2x2-brick-blindness, thought I got them all early on and every 5 minutes for the rest of the evening I would find another one. Either that or they're breeding, which would be no bad thing!
Occasionally I find non-Lego, but I caught most of it in the pre-clean rough sorting, and very little has come out in my detailed sorting. Got about a small margarine tub's worth of non Lego.
But I really enjoy the sorting, it's like Christmas has come early whenever I get through a big freezer bag that's full of something really useful like 1x12 plates!