1. Looks for hotels favored by Indians - helps if you are keen on Indian food, Hindi music and general comfort. Gold Beach, Flic-en-Flac, where we stayed, is such a place. Recommended.
2. Things are generally expensive - food, travel, phone cards. You can save a lot on food, by having a heavy breakfast and dinner (included in half board hotel bookings) and carrying snacks, sandwiches for lunch
3. Swimming is a must, if you want to enjoy Mauritius to its fullest. I couldn't swim well in currents, so snorkelling was quite a task. So, you can't enjoy the under-water wonders. Also, as a rookie swimmer, you have to be wary and can't explore even the shallow depths of the ocean. Atleast, carry a simple float or tube, so you don't feel left out.
4. Net access is not widely available. In some malls (esp in the capital, Port Louis), there is free but limited net access.
5. Always book the rides or water sports activities through an official tour operator. It's safer and less chance of been cheated. There is that typical desi ethos of not honoring commitments, so be sure to confirm repeatedly
6. Haggle everywhere and anywhere. Ask for a discount and you will get it. In markets or road side shops 1/3rd the quoted rate, in malls and bigger shops, a bit less (discount).
7. Try the untrodden path - Bike, walks, public bus rides, local markets.
8. Language and food is not a problem. 57% Mauritians are Hindus, so food is heavily India-centric.
9. Expenses for two persons, should be not more than 1 lakh all inclusive