Ear plugs

Like such as getting mic placement on drums and guitar and whatnot, so you don't destroy your sense of hearing good tones when you go back into the control room?

Mic the cab/drums before you have loud sounds coming from them.
 
For those of you that are in the US, the Elacine ER 20 are the same as the etymotics and the Hearos High Fidelity. I'm going to a Parkway Drive show in a couple of days so I picked up a set of the Hearos from guitar center. They have 2 different sizes. The smaller ones are called "High Fidelity long term". If you don't have huge ear canals the Long Term's are probably for you.
 
In case anyone wants to know, Amazon.com has a good selection of the Etymotic ER20's for $12.95 or less per-pair. Just ordered two pair myself can't wait for them to come in and try them out. The HEAROS versions of the ER20's are like $15 a pair, they are on Amazon as well.