If you are familiar with my training material on Seatopenpoker.net you know that I am sometimes a proponent of just flat calling preflop with AK in order to keep a lot of the weaker hands in the pot. Say, for example, an early position player raises with AJ and you three bet him with AK from the button. He folds his hand and we lose the value of getting him to commit money if we flop and ace. Sometimes we have to continue on on certain board textures however even when we do not flop a pair.
When we flat with AK as a field caller and an ace flops I believe, on somewhat disconnected boards, we should fast play the flop just like when we flop a set. Say, we just call with AK against a mid position raiser in the cutoff. The board comes out A♦ 6♣ 3♣ and the preflop raiser makes a continuation bet. This is a perfect spot to play your hand just like you had a set of sixes or threes. The board is drawy and a lot of your opponents will not fold hands with an ace in it after they raise.
The other key thing to playing AK for big pots after flatting preflop is to value bet every street. Raise flop, bet turn and bet river. You’ll see some strange looks from other players at the table especially at the lower levels as they would never see anyone value bet so thinly with a top pair hand. But this does not matter. Value betting the best hand is one of the keys to increasing your win rate in No Limit cash games. And a disguised AK on an ace high board is very often going to be the best hand.