A region that lives on one line
On Star Battle, a region that lives on one line owns that line. If a region’s remaining cells all sit in one row, that region takes the star for that row, so the rest of the row is empty. Mark those cells as dots.
The same is true for a column. If a region’s leftover cells all sit in one column, that region takes the star for that column.
The other way around works too. If a row’s remaining cells all sit in one region, the rest of that region is empty — that row will take the region’s star. Do the same for a column.
This is the first extra idea after finishing a line or region and marking neighbours. On Beginner 6×6 you may not need it. When you do, look for a skinny region, or a line whose open cells all share one region.