Any "tricks" flying with AA?

Fly weekly for work - tuesday return thursday - and wondering if there is anything more fequent flyers know that i should. Was flying SW but a change in destination has me using AA weekly. Obviously getting my FF miles but corp card doesnt pay for seat preference and it sucks having to spend $60-$100 a week to make sure i get an exit row or aisle seat as im a bigger guy a 6'4 and 275lbs. Any other tips or tricks I should know about?