One thing I suggest is that if you can fly to where ver you are going for under about $250, just pay for it, and use the FF ticket for the expensive trips. For example:
I'm flying on a first class ticket next year EWR to LAS, the coach ticket is around $380, I didn't even price the FC ticket, but it has to be up around $1500, I'm using 40,000 points. A couple years ago I flew PHL to SEA on a FF ticket, the coach fare was $500, it cost me 20,000 points.
A month ago I flew EWR to YYC First class. The ticket would have cost over $2800, a coach seat was around $800. Good use of 40,000 points, as opposed to using them on 2 coach seats to MCO that would have cost under $400 total.
Figure that points are worth about 10 cents each, and go from there...
Anne