Max's tape trip works well!
A center punch on a Sharpy pen mark works good for locating them also.
You can buy the "self-drilling" screws that do a good job also, if you use Max's
method or a center punch to locate the positions of the holes.
Any jobber's length TI nitride drill made for steel works nicely.
If you are going to be using the MB Trilobular screws, look for a combination
6mm drill/tap. It drills the correct size hole and threads it for you.
You can also drill them slightly small and run a 6mm x 1.0 tap thru the hole first,
before screwing in the MB Trilobulars.
If you are going to be putting alot of weight on your screws, put back up washers
and nuts behind them where ever you can get to.
the rivnuts work nicely, but be sure to get the correct drill/reamer and installation
tool.
Hope this helps,
Roger