Well there are some things to look at and to be careful of which is mileage expiration and extending them if you plan to use them.
- Asia Miles. I don't fly these guys much, so we had 80K miles and got a nice pair of sun glasses, a decent one cent per mile
- Qantas. This also expires every 18 months. The easiest way to extend is to buy a gift card or do a unicef donation.
- Virgin America. Expires every 18 months as well. Easiest way to keep it up is to buy something via the Red Store where you can buy an itunes email gift card for instance.