How to prevent NB Alternator belt sqeel?

Ive had my 2002 Miata for a few years now, daily drive it. And I swear its every 4 months or so I gotta go adjust the belt tension, its like with every season change, every major temperature or weather change outside. Super squealy right when it starts, and if I have a bunch of power draw going, lights, radio, ac/heat, all at once. And after running for a bit, letting the idle RPM stabilize and lower, let the engine warm up, it calms down. But its super annoying. Adjusting it isnt hard, hotten pretty good and routine at it, but its annoying that I gotta do it so often, especially since its a small hassle to get the tension right, and ive never been confident ive gotten ir right, and when I replaced my alternator a year or so ago im afraid it had an early death from over tightening the belt. Tomorrow me and mt girlfriend are doing some work on the cars, gotta change her oil, fix something up with her heat before cold weather starts, so whole at it im finally gonna lift my car up and fix the belt ive been ignoring most the summer. And if I can finally permanently have a lasting fix that would be cool. I get having some stretch to deal with on a new belt, but this belts a few years old now so id think i got the new belt stretch out, perhaps the tensioner just vibrates itself a little loose over time? If anyones got a fix that'd be cool.