I have seen many good search strings in Logos Pro tips, Mobil Ed courses, etc. I also have made some pretty complicated ones myself. The trouble is, six months later I can't recall exactly how I did it. It would be nice to be able to save our search strings. I know we can save the results as a passage list, but the underlying search string is not there, so that we could edit it if we choose.
A work-around is to copy and paste the string into a notes file. However, I find this inelegant.