Please note that these are general rules; they might not be advisable depending on the rules used, game progression, and the expertise of the players.
FAIR PLAY
It is accepted and in the official rules that you may ask your partner if you may go out. Yes or no are the acceptable responses.
Table Talk is communication that influences your partner's play. This is considered cheating. Please don't table talk.
In games that allow an early end, it is polite to attempt to get a consensus with your partner. Games are rarely impossible to win.
TIPS
At the start of any game, make sure you know what rules are in play and what is required for contract, as well as how many rounds there are.
How you open and play is somewhat determined by if you are playing with open or closed melds (7 cards max), and whether the wild meld is required/optional or not allowed.
When playing in teams, remember that you should be working together to help each other get to foot, get contract and go out, hopefully ahead of your opponents.
With that in mind, think about what you are playing and when. One example is, if you are the only player in foot, closing melds may not be the wisest choice....
In a closed meld game (7 cards max), melds with 5+ cards are blocked meaning that you or your opponent can't pick up the discard with a pair of that value. However, depending on the rule set, this may need to be balanced against where wild cards can be played.
Picking up the discard pile can be very helpful to open new melds; however, if it is full of black threes, it can also stop you from getting to foot or going out. It is wise to pay attention to what you are picking up.
Hand and Foot is a game of both strategy and luck. The best players adapt to the cards and their situation in the game. Be flexible.