Most often one mag in a 1911 IWB and one in a pouch on my belt. Sometimes I'll throw another in my pocket just for the heck of it. 230gr. 45ACP, 6 or 8 rnd single stack depending on the gun.
On road trips, I often take my CZ-40 in the car for a BUG to my primary CCW or for an extra gun to arm a passenger if ever needed. In that case, I'll have one mag in the gun and two more in a mag pouch stashed in the car. 165gr. 40S&W, 10 rnd double stack.
Just around town, especially in the summer, I'll have my J-frame in pocket with 5 .38 Spec. +p in the cylinder and one or two 6 round speed strips.
As you can see, I always carry reloads. Mags fail, ammo fails, nasty people fail to have the proper respect for the ammo you are carrying.