I follow the same routine every time. Wallet, watch, phone all go into the backpack before I get in line. The only things in my pockets are my ID and BP. Occasionally I get a screener that tries to tell me to take my belt off, but I wear a Frequent Flyer belt for specifically this reason. Never had an issue. One time I did forget that my wallet was still in my back pocket. Three metal cards is apparently enough to set off the WTMD at BNA.