If you are asking about recruiting within the current student body, start with the younger grades. You will most likely need to shift the culture of the school to where band is viewed as a worthwhile program.
There was an article in the August 2021 issue of Southwestern Musician (the TMEA magazine) titled "Rebuilding a Small School Music Program" linked below. The article begins on page 20. When you have 5-10 minutes, glance through it. There are some good tips in there.
If you are talking about outside of the school, be careful using the "R" word. I don't "recruit". I let our results and the quality of the program speak for themselves. If people want to be a part of this program, I'd love to have them. We don't offer scholarships for band (it isn't allowed anyway). There is financial assistance for attending the school where I teach, but it is needs based and has nothing to do with the courses a student selects.
I'm in the same situation. Our admissions head is a former band director so he helps talk up the program when he's visiting schools and always makes sure to bring potential students to the band room. We also hosted an honors band event this year to help gain interest and next year I'm going to visit some schools with him to talk about the program myself. Whenever we have a school event for potential students either the band is there or I am there to represent the program. But, honestly, a lot of it is word of mouth and getting younger siblings interested for when they move to high school.
