Describe me as a minimalist, yet I dropped most of GUI solutions and by experience, I prefer to use the following strategy:

• fire up you command-line interface client (terminal, iterm, ...)
• identify the path of the drive that is full: /, /Volumes/data and change to this directory (that is; cd \)
• ask for the size in the hierarchy and sort it: du -k |sort -n

It is a quite universal law that "small files are many, large files are a few, but these are very large" - such that you may quickly find the culprit.

Describe me as a minimalist, yet I dropped most of GUI solutions and by experience, I prefer to use the following strategy:

• fire up you command-line interface client (terminal, iterm, ...)
• identify the path of the drive that is full: /, /Volumes/data and change to this directory (that is; cd /)
• ask for the size in the hierarchy and sort it: du -k |sort -n

It is a quite universal law that "small files are many, large files are a few, but these are very large" - such that you may quickly find the culprit.