Hello All Quarantine Methods

Hello I'm new to the hobby. I just finished cycling a 65 gallon reef tank with 70 lbs of live rock and a 15 gallon sump. I was wondering about quarantine methods. Do you automatically treat/medicate new arrivals in a quarantine tank as a precaution? Or is it advisable to see if any visible symptoms develop before treating the tank? If you automatically treat new arrivals regardless if they are showing symptoms or not, what do you use?
Thanks
J