The goal of Pyramid is to clear as many boards as possible by tapping any two cards that add up to 13 (or one King). You can cycle through the deck 3 times before it's exhausted. Then, just tap the Deal button to have a whole new board dealt. You can do this twice per game. Clear a board (7 rows) and a new board will be dealt.
Keep starting a new game until you see a board with a few Kings in it and check that the cards at the top of the pyramid aren't covered by the cards that you need to pair them with, as that could become a problem later.
Run through the entire deck making a note of what each card is without pairing any cards, and then use undo to reset the deck. That way you know what is coming up. Always pair cards on the board before you pair a card on the board with a card on the deck. Only pair cards on the deck (for additional score) if there are no cards left on the board they can be paired with.
If you don't clear the first board, start a new game. Once you have cleared the first board then you only need to clear 14 rows on the remaining 3 boards.For those with Windows 8
You can download Microsoft Solitaire Collection (Win 8)
for free and start a game and play until you have cleared 21 rows or more, but don't complete the game. Load the cloud save on the phone and the achievement will pop up straight away before you have finished the game.
Each new board is random, so just before you clear a board or tap Deal on Windows 8 you can load the cloud save on your phone and see what the next board is like. If you don't like it just quit the game and reload the cloud save to get a different board. You could then transfer this save back to Windows 8 so you can do it again at the end of the next board. Using this method there's really no end to the number of boards you can clear.