This is how I'm mounting mine. By no means is this "the" preferred way. Just like I could not tell you how to make the perfect sandwich. I had access to some teflon sheets and cut them down to approx 1/2" thick x 1" wide x 9 3/4" long. I cut reliefs to mount them to the box and counter sunk the holes that would house the screws, did not want any of the screw heads (I used #8 pan head stainless steel) protruding and contacting any of the solder joints. After the strips were mounted, I took a few extra rubber grommets I had to put in between the board and teflon strips to act as a shock absorber (No pun intended).
I have heard of people using wood as stand offs. I myself would not, (without some kind of non-conductive standoff to keep the board away from the wood) because wood retains moisture and we all know that water and eletricity do not mix well. Anything 'non-conductive' would be a good choice, and I'm sure more of us will offer some excellant examples - Heck, if someone builds a better mouse trap - I'd use it!!!
Just my 2 cents
Bill A.