When swiping in any direction, the entire level moves. Try to match as many squares as possible with each swipe and maximize the empty spaces. The more empty spaces, the easier it becomes to match more.

Empty moves are those that result in no matches. Reduce these as much as possible because each move you make places an extra tile randomly on the level.

Balance your growth and do not have one huge number and many small ones. Try to have about two of the highest level numbers at all times ready to be matched, followed by increasingly smaller amounts also in pairs and ready to be matched. If you get a single number to very high values, the level might fill before you get a new one to match it with.

Focus on matching the small numbers (2s and 4s) that you get for awhile. Do not allow them to accumulate space on the level. While matching and mixing the small titles, you will be creating bigger matches.

Swipe the level right, left and down only to build a nice base of tiles at the bottom. Then make a few moves and get some chains after swiping up to get very high numbers. Then, use those three directions again and repeat the process. This reduce where new tiles will appear and makes them easier to use.