. More info on their implementation here
Do them before every single workout, first thing in the warmup. Make sure you are barefoot! Foot/ankle problems manifest themselves up the entire kinetic chain, and your flat feet potentially signify some weakness in the intrinsic muscles of the foot.
Walk barefoot as much as possible. Jump rope barefoot. Get some Nike Free 3.0s for daily wear. Concentrate on lifting the arch(-es) in any squatting movement (you'll need to start unweighted to learn how to do this).
Start all of those things easy, do less than you think you need to.