One thing to also keep in mind is keeping your expense records seperate also.
Save every receipt.
I Keep an envelope in my purse/backpack just for that purpose. I also print out all online purchase receipts and keep them in a folder on my desk. A couple of my friends have been audited and it is a nightmare if you don't have records for validation.
I've learned from their IRS experience and have changed my haphazard ways.
I am now a believer in the priceless value of a receipt! Weekly, I visit my Sacred Drawer of the Business File Cabinet and happily tithe my every business related ticket and receipt. I truely believe in...
SALVATION THROUGH DOCUMENTATION!
This won't keep me from getting audited, but it will have them swimming in paperwork instead of me!