My FR rules of thumb are:

- Consider for short flights up to 2.5 hours
- Take hand luggage only (Make sure it conforms to all their rules)
- Flying to smaller / out of the way airports can save a lot of time (depending on your destination....)
- Their first out last in flights from UK maximise weekend breaks value in your destination - had many w/e breaks in new cities for under 100GBP ai without needing to take any days off work if you book ahead and plan well
- Look out for empty Exit row seats - many people think they are reserved and they can't sit in them
- Take your own food on board
- Take a paper / book / I-Pods etc. to keep you engaged for the whole flight
- Expect what you pay for - anything over that is a bonus!