Toilets, Sinks, Showers, Tubs and Disposals - drain problems, tub and sink

back again for DIY advice (please spare me the "get a new plumber" advice).
My plumber just cleared the tub and sink drains of some massive hair clogs, and I'm guessing he also adjusted the respective drain stoppers.
First, the tub now will not hold water for a bath. I've seen this fix on Ask This Old House, but wasn't paying close enough attention. is the adjustment simply trial and error, or does anyone have a tip?
Second, the sink won't drain. I thought this was a problem with the pop-up drai, but, while writing this post, I removed the drain plug completely and it still won't drain. It must still be clogged, so I'm going to try snaking it.

If you have the type tub drain that has the lever on the tub wall, you will have to remove the two screws on the faceplate and adjust the wire linkage that lifts/drops the barrel stopper. Be careful not to drop the gasket on the outside of the tub (back side of faceplate).
If your clogs seem to be hair, you can use an exzyme drain cleaner such as Draincare. Enzyme cleaners cling to and "eat" organic clogs. Usually, soap residue helps the hair to cling to the inside of pipes. Good luck.

thanks; I'm gonna go out and buy some Draincare and try it in the sink, as snaking and plunging is bringing up some nasty black gunk, but still no success.....