Great question, so a lot of times you can purchase lists from Propstream, HOA Vacant, List Source and other providers. The ones I mentioned are personally the ones I use. Most of the time the list you purchase other people will purchase so sometimes it's good to create a niche list.
An example would be knowing that their is a ton of uncertainty in the Real Estate Market, it may be a great time to reach out to "Tired Landlords". That layout would look something like this: 5 or more years of ownership, not listed on MLS, Location out of State and Local, Estimated equity 50% or more, owner type individual. This can be pulled from Listsource, Propstream all kinds of places.
Hopefully that helps and answers your question, the biggest advice I'd say is don't overthink it. Purchase a list of about let's say 500 addresses on it. Then skip trace the list, and export that data on an excel sheet and start reaching out to them via whichever campaign route you'd like to go. "Consistency brings out the Winners".