If you have been dealt an Ace and a King and neither of your cards is paired on the flop, all hope is not lost. There are several things that you must consider in order to determine the actual value of your hand in any given situation.
What to Do?
You must always remember that an Ace-King combo is a hand that relies on the flop to really come to fruition. It is not a hand at all without some sort of improvement. Also, you will only be able to create a pair on the flop about 35% of the time. Knowing the right times to go all-in on a hand or to hold back--perhaps even folding--is the key to making the most out of an Ace-King combo.
When You Miss the Flop:
If your opponent bets into you, you should always fold unless the odds are in your favor. If the flop gives your opponents to build a straight, they have an advantage over you that cannot be beat.
If there are more than two opponents betting against you, it is also best to fold.
If you are absolutely committed to the pot, you should always move all-in. For instance, if your pre-flop raise was very high and you only have enough chips to back that up, you should put everything up for grabs.
By following the advice here, you will undoubtedly be able to make better decisions regarding your Ace-King combo. Missing on the flop is not always a deal-breaker, particularly when you are able to play the cards right!