Easiest way is to set the engine by the TDC mark on the flywheel. Now either both #1 valves are closed or both #6 valves are closed. I like remembering it this way;
You have 12 valves starting #1 cylinder with both valves closed (all the way up);
Adjust valves 1,2,3,5,7,9. Turn the engine over 1 revolution so the TDC marks is on the flywheel again. Both #6 valves should be closed. Starting in reverse, adjust valve 12,11,10,8,6,4. All done.
I think thats the easiest method of remembering. So long as you start on the end of the engine where both valves are closed and the flywheels on TDC, either #1 or #6.
