Hi karl, Procedure I use is this, as you may know, you have to adjust tappets when cams are positioned on their lowest point or base. Given that #1 and #4 are companion cylinders, so are #2 and #3. Meaning they are in time with each other but doing opposites and so are the valves. #1 exhaust valve and #4 ex valve, #1 inlet and #4 inlet and so on, all doing opposites.
I start with #1 exhaust valve, it will be fully closed and can be adjusted when #4 ex valve is fully open, in down position. Then do the next, turn engine over till #4 inlet is open and adjust #1 inlet. You can save a bit of effort by doing more than one at a time when you see other valves that are open to adjust their companion valves. Mark off the ones you do with dab of grease. I normally remove plugs and select 4th gear and pull car along to turn engine over.
Hope this helps! Rob.