
The object of the online game Freecell is to use all cards to build up the 4 home cells in ascending order starting with the aces. Free cells (4 cells in the upper left corner) can be used as temporary placeholders for just 1 card at a time.
As the online game proceeds, the 4 free cells (upper left) are only used as an intermediate holding place where any free card can be temporarily placed in order to access cards buried in the columns. A free cell can never contain more than one card. You can also move any free card into an empty column if any such columns exists.
Do not use free cells unless you have to.
Do not put those cards in the home cells that you might need in building your columns. Cards from home cells cannot be taken back.
Look for low cards (ace, two, etc.) buried high in the columns and develop a plan to free them up.
Try to empty one of the columns. It can serve as an extra free cell.