The ultimate aim in any hand of Pai Gow is to try and win both hands – the five-card hand behind and the two-card hand up front. If you do so then you win all of the pot, minus the 5% commission. If you don't feel you can win both hands then you should try to make sure that you win at least one of them and break even with the dealer. An ability to judge when it is best to go for both hands or to settle for winning just one will be key to your success in Pai Gow Poker.
Here is a brief breakdown of the kind of combinations of seven cards you may be dealt, and the accepted wisdom of what you should do with these hands:
Four Aces and the Joker: If you also have a high Pair, such as Kings or Queens, to go with these other five cards then you should play the high Pair up front and keep the five Aces behind. Otherwise you are recommended to keep three Aces in your five-card hand and play two Aces up front.
Four of a Kind and Three of a Kind: If you are fortunate enough to be dealt Four of a Kind and Three of a Kind then it is recommended that you split the Four of a Kind to send a Pair up front and keep a Full House behind. If the Four of a Kind is a very low number then it may be better to keep it as Four of a Kind and split the Three of a Kind to send that Pair into your two-card hand.
Four of a Kind and a Pair: Keep the Four of a Kind for your five-card hand and play the Pair up front.
Full House and a Pair: Play the highest Pair up front.
Full House: Play the Pair up front and keep Three of a Kind behind.
Straight or Flush: Use your Straight or Flush for the five-card hand while still playing the two highest possible cards up front.
Two Three of a Kinds: Keep the lowest Three of a Kind behind and place a Pair from the highest one up front.
Three of a Kind: Always play the Three of a Kind in your five-card hand unless you have three Aces, in which case it may be best to keep a pair of Aces and use the other Ace and the next highest card to make your two-card hand up front.
Three Pairs: It is recommended that you play the highest ranking Pair up front and keep the other two Pairs behind.
Two Pairs: If your Pair is between 2s-6s then split it and play the low Pair up front, unless you also have an Ace and a picture card, which you can then play up front and keep two Pairs in your five-card hand.
If you hold two medium Pairs (between 7s-10s) or a low Pair and a high Pair (Jacks or higher) then split them, unless you have an Ace to play up front.
If you hold two medium Pairs or two high Pairs then you should usually split them.
If you hold a pair of Aces and any other Pair then keep the Aces behind and place the other Pair up front.
One Pair: Keep the Pair behind for your five-card hand and place the next two highest cards up front.
No Pairs: This is the worst possible hand in Pai Gow Poker. All you can do is to keep your highest card for the back, place your next two highest cards up front and hope for the best!