This doesn't really have anything to do with Oman per se, but I think all these things are more important when you're an expat and in a difficult place to live.
1. Be nice to your officemates. Make them coffee. Bring in a treat now and then. It spreads good vibes and it's easy to do.
2. Get up early and at the same time every day. Routine is important. Just get your ass up even if your bed is super comfy.
3. Be pleasant to locals, but if you don't feel like it, politely decline coming over for coffee and Helwa.
4. Get enough sleep.
5. Learn to say "No" to everyone. Saying no politely can be an art. Develop it.
6. Don't feel bad about the little things that keep you sane. Even if it's watching Rachel Ray everyday (dear God...).
7. Eat lots of yogurt. This country does a serious number on your stomach.
8. Don't just sit at home and do nothing (if you live in the boonies I like me). It's hard but even just go for a walk. It helps.
9. Let yourself be miserable sometimes.
10. It's okay if you have to crawl under the covers, hide, and pretend you're in la-la land everyday. Just make sure you make a plan and get up.