Tip on starting a snail mail campaign?

Jeffrey, if you need someone to handle it for you from A to Z, from designing to dropping it off in the mail, there is a Minuteman Press franchise shop in my area that does an excellent job for as low as 50 cents per mailing (including postage), and I know the owner. Let me know if you (or anyone else) need an introduction. https://minuteman.com/us/locations/ca/torrance21/

Keep it personalized in order to stand out. That is in fact the very reason you are sending a physical letter. You want to cut through the clutter and stand out. A physical letter that looks like it was mass produced, sent through a mailing company doesn't provide that personal touch. I hand wrote every address, and hand signed every letter. It can be time consuming, but you want the business owner to see your letter and know that it's different.