I'm mainly posting this up for Stuh84 but it's here for anyone else that may want it.
First up is a great tutorial on etching & painting pedal enclosures
Then secondly this is one of the things i use the most for knob positioning and final layouts a good old vector pack with all knobs/jacks enclosures & pots etc in the actual sizes that you can just setup how you want then print it out and toner transfer it onto your enclosure to have a ready made drilling template and graphics!
Just noticed, the second PDF is the same as the first. The etching one though is brilliant