What color is the smoke you're seeing?
Blue smoke at start up means you've either got bad rings or bad valve stem seals. Do a compression test... twice. The first time just do it normally and the second time add a little oil to each cylinder as you test (When you add the oil use a small tube to get the oil pouring down the cylinder wall and not just on top of the piston or it won't do any good. The pistons are dished and the oil won't reach the rings where you want it otherwise.). If the compression test results are hicher after adding some oil to the cylinders the rings aren't sealing well; the valve stem seals could also still need replacing. If the compression test turns out within specs then the seals are one of the first things I'd address.
To verify that this is where the oil is going clean the inside of the throttle body thoroughly. Then over the next couple days keep checking it. It's natural for some oil to enter it via the PCV system, but there shouldn't really be much accumulating in just a few days.
Lastly, when you pull the spark plug wires out to do the compression test check and see if there's oil pooling around the spark plugs, leaking valve covers often leak oin into here causing misfiring.
EDIT: Compression testing proceedure:
http://www.cygnusx1.net/Supra/Librar...ection=EM&P=20