Build a Descending Chain
Level: Basic
Arrange tiles so values shrink the farther they are from the corner.
Lining up tiles in a single row from largest to smallest, starting at your locked corner, is called a "chain." For example, fill the bottom row in descending order like 128, 64, 32, 16.
With this layout, newly spawned small tiles attach to the end of the chain, and matching values merge one after another, growing the whole chain a step at a time.
Keeping the chain in a single row (or a two-row snake shape) is the key to a high score. If the chain breaks up, the big tiles can't reach each other and merging stalls.
Related Strategies
Intermediate
The Snake Pattern
Keep a zigzagging, descending layout across two rows.
BasicProtect Your Max Tile
Avoid moving your biggest tile unless you absolutely have to.