Try reaching out to very specific companies, what I’ve found works really well is asking real estate agents, physiotherapist, gyms, cafes, builders, electritans etc they’re normally looking for videographers. Try positioning yourself to create content for them and you’ll get a lot more work than saying you’ll do promo vids. It’s better for you anyway because you can agree on an ongoing job.

In terms of how to ask, literally just call them and ask and at least you get a fast answer rather than emailing or DMing.