Josh -- so many opinions out there.
perhaps this will help (but I am 45) so it might be different for me. My face muscles are the ones for me that need rest. they seem to hold the cheeks in and the lips (aperture) together for higher range. High range is also faster air, etc. -- lots of posts about that. (***very important -- high range is very, very light pressure also***) this will help range and prevent injury and cut/bruised lips.
anyways -- holding notes long and soft -- repetetively, even at a lower range -5-6 notes below your max, and lower - helps me (like for 5,10,15 minutes) - then rest (5 or 10 minutes).
I rest within my practices. On heavy days -- I also try to triple tongue all the scales, lip slurs, long notes, etc. -- usually a 3 to 4 hr+ practice --- then the light days--- I go 1.5 to 2.5+ hours, softly, slowly -- trying to keep all the face muscles moving a little bit, but not overworking them.
I do admit -- I am a comeback player -- so I am working on everything including musicality,endurance, and range -- so for me it is a "burn" the muscles workout ((without causing yourself injury --no blisters, no pulled muscles, etc.) -- then an easy day to recoop -- and so far it seems to be paying dividends
oh -- and get plenty of water and protein to keep the muscles in find shape.
hope that helps -- and if need be (soreness persisting) -- actually take a day off.