Here's some things not to do.
1) Don't tell the auditor in advance that you won't be providing food. (It's pretty **** mean not to provide food in the first place, but at least let me know so I can sort myself out...

)
2) Don't drive us 30 minutes each way to a restaurant, which then takes 45 minutes to serve the food. (Especially when we have already made it clear that due to previous history of similar shenanigans we are staying put until the audit is finished. Auditors love to finish really late, especially when they then have a 2-hour drive home).
3) If you are located in a foreign country to your guests, try to find out in advance what food will be suitable/palatable.
Especially, if you are in a developing country, and bring food in, try to avoid serving salad (etc) as a specific course. We want to avoid water-washed food for protective health reasons, but we also don't want to cause any insult.
On the flip side:
If your auditor is with you for any length of time, consider inviting them out for an evening meal. At the very least make recommendations of decent/interesting local restaurants. We see enough hotel and chain food, any variety to that is good.
Additionally the social side can lead to better customer relations and an improved overall audit experience for you.