No-trump play can be difficult. What most expert recommend is that you should first count your top tricks - tricks you could cash without losing the lead. Second, subtract that total from the number of tricks you require to make your contract. Finally, decide from which suit (suits) you are going to establish those extra tricks.

EW reached 3NT contract on the hand displayed above. East has 8 top tricks. Both minor suits would provide opportunities for extra tricks. The diamond suit particularly would be the one to tackle immediately, as the Queen is the only missing honour.

If interested, you could try "Play it again" feature to have a go and replay the hand.

When playing a suit contract, many experts recommend to count the losers in your own hand and work out whether to ruff them in dummy or discard them on side suit winners.

The hand above was played in 4♠ by South, The declarer has 3 club and 2 heart losers. The long diamond suit in dummy provides opportunity to discard losers.  So the plan should be draw (with care) 3 rounds of trumps, assuming 3:2 split. 4:1 split  also need to be considered. 

You can use "Play it again" feature should you be interested to have a go.