This saves draw cards and makes clearing the end of the pyramid less dodgy in the end. Regardless of difficulty, you should try to use the cards in the pyramid to get rid of other cards.
Try to match cards that reveal more cards over ones that don't, as you'll want to get rid of as many cards as possible as fast as possible.
In endless games, you'll be able to clear as many pyramids as possible until you are unable to solve the game three times total. Only do this if you don't see any more of the two cards in the pyramid. Cards in the draw and waste piles can be matched together, which is only necessary for more difficult games, but can be nice to clear out your pile if you don't need either card anymore. You may only flip through your draw pile three times before the game ends, so you need to be as efficient as possible with what you have.