1997 Toyota Corolla ruff idle

Any valve train noise? Ticking, clanking?

You must replace the valve shims in the exact order they were removed. If not, it is possible yo have a valve not completely closing, or opening.
Also recheck the timing marks on the timing belt side, and I would run a compression test to make sure the headgasket is secure.

You will have to measure valve clearence on each valve (cold engine).

Write down each clearence measurement and record cylinder # and wheather intake or exhaust.

The manual will list the valve clearence range.

Determine which valves are out of range.

You can then use a special tool set to move the shims to correct place, after measuring shim thickness, comparing it to shim thickness of wrong shim, subtracting the measurements and determining if that shim thickness on that cylinder would bring valve clearence within spec.

While you can buy new shims from Toyota, they are about $10 each, sold individually. New shims would be easier but more costly. If you measure valve clearence on #1 intake and it is.002 and spec is.008, you would measure shim thickness of bad shim and get new shim.006 thinner.

You want to get this done ASAP, because if you have a valve too tight, you can damage the camshafts.