I do not want to pay annual fees unless the fee is worth it. What would some of you veterans suggest for the following situation?

I currently have the following cards with their 1-year anniversary dates:

Chase Sapphire Preferred: 4/20/2013
Chase Priority Club Select: 4/13/2013
Chase United MileagePlus: 5/31/2013
AMEX Starwood Preferred: 4/17/2013
AMEX Starwood Preferred Business: 4/19/2013

My credit score is a 759 (creditkarma.com). My current go-to spending card is the Chase Sapphire and I make 1 small purchase per month on the rest of the cards to be a good customer.

Lastly, I have not used any of the earned miles/points yet. Suggestions on how to not lose them?