Yep, there sure are many different points of view as Joe said. Also, I tend to agree with Marilyn about diagnosing illness. Many illnesses, such as crypt, can be suppressed by the immune system until such time that the fish is overly stressed. As an example, crypt ordinarily prefers the blood-rich tissue in the gills. As long as the fish is healthy it can suppress the parasite and live a long life without you ever seeing a white spot. I have personally had fish in my QT without copper and witnessed them for weeks eating and appearing generally healthy. Then when I moved the fish from my calm & peaceful Qt to the DT all hell broke loose. The fish was bullied a bit which caused it stress, which lowered it's immune system...which caused the crypt to spread to the rest of the body quickly...ultimately killing the fish. So it really boils down to personal preference regarding what you want to do.
Generally speaking, you want bare-bottom, no rock or sand. You will need hiding places so cutting some large pvc tubes (like you seem at most of the lfs's) is the best because it gives them a place to be calm while you can still see them.
Here's a link to a very comprehensive plan for QT. The guy who wrote it is one of the most respected people in the industry when it comes to fish disease, diagnosis and treatment. Personally, I only digress from his believe to only QT one fish at a time per tank. I usually try to buy 2 fish at a time and QT them both together in my 20G. if I already have a fish in QT and then add a 2nd, then the clock starts over for the first fish who will stay in QT for the whole session to cover the 2nd fish.
http://www.reefsanctuary.com/forums.../23584-fish-quarantine-process-step-step.html
Here's another good read about Qt'ing. This one goes beyond just fish and also talks about corals. Personally, I dip coral and not QT them...
http://www.reefkeeping.com/issues/2004-10/sp/feature/index.php