Check to see if your city is using chlorine or chloramine, get a dechlorinator suitable for the disinfectants your water requires. If they use chloramine, I recommend Seachem's Prime. Prime stops binding ammonia after ~24 hours, so it's best to wait until just before a water change to dose your aged water with dechlorinator.
My city uses chloramines. In order to ensure the ammonia is bound long enough for my filtration to handle it I dose my aged water with prime while draining my tanks. I'm not a fan of dumping straight ammonia into my tank.
My routine is generally:
A day or two before a water change I fill bin containing a heater and small water pump with water near what I need in the tank (the hot water from our gas water tank costs less than heating cold water with an electric heater.)
Check temperature of new water vs tank water (keep within 1-2F)
While I'm draining my tanks, I dose the aged water with prime, giving it a good 30-60 minutes to react with the chloramine.
Once the tank is drained the correct amount ( I have tape on the tank and sump) I turn on a powerhead in the aquarium and start pumping new water in to the tank. I use the powerhead to mix up the old and new water more effectively with the thought that the PH is slightly higher and pockets of different PH would be stressful.
I don't use a powerhead on my smaller tanks, since the incoming water creates enough current to traverse the tank, but on the 180 it's easy to see the currents barely travel halfway.
