As a kid in the 1970s I did not use any product in my hair, but I did use a comb, though I don't recall ever carrying it with me.
In the 80s and 90s I used an assortment of hair gels.
In mid 90s I began getting my hair cut very short, and now I just use Crew Comb in my hair. If needed, I use a brush or just my fingers, but the gray in my hair seem to be good at keeping it all in place, mostly.