It is really important to keep good records of what you are doing and your results as you go. It is not uncommon to have to revisit and unpick your search and this is made infinitely easier if you have keep good records. Always keep in mind that:
A not exhaustive list of things to record incudes:
Saving your search with the database provider can help here, especially if you annotate the description field with key information. Importantly, remember to note the name of the database in which you undertook the search as the platform you are using may provide more than one database.