One trick I learned is to create a big random file (must be random to ensure no funny compression filesystem tricks out smart you) called something like BIG_DUM

One trick I learned is to create a big random file (must be random to ensure no funny compression filesystem tricks out smart you) called something like BIG_DUMMY_DATA_SAFE_TO_DELETE. When you find yourself in a catastrophic space situation, you can delete the file and have a less panicky recovery process as the immediate problem is gone.