My QT tank has a heater, thermometer, and a HOB filter. I put in a couple of sections of 2" & 3" PVC pipes for hiding places. Some of the fish actually hid UNDER the pvc... not exactly what I had expected, but they seemed to like it under there.

Test frequently and do water changes as necessary. That's it!

(You could also run a HOB filter with a sponge in it on another tank for a couple of weeks to build up good bacteria and then move it over to the QT tank when you bring your fish home.)