Many members of the Guild of One-Name Studies and other genealogists, report that they become fascinated with surnames following encountering a genealogical brick wall or because of intrigue with a particular surname. Therefore it seems likely that you have material already regarding your surname of choice.
The tip for day three is access what material you hold already, whether that is notes from relatives, records you have gathered during the course of research or those that have come down through the family. Establish if that material is electronic or physical.
Consider when you did that previous research, as maybe since that time, records have come online and available. Perhaps the records were always available, but a new search now, reveals more results.
Don’t forget to add the assessment to your research log. If you don’t have a research log then there is one HERE that you can use and adapt to suit your needs.