I'd recommend doing them someplace natural like in the mountains or beach and away from straight people. All of my best shroom trips have been out in nature. If you have to be indoors rent some good trippy movies, everyone has their favs but I'd recommend Yellow Submarine and Evil Dead 3 (Army of Darkness). Most of all be with friends and make sure you don't come into contact with your parents or other authority figures.

As far as smoking on shrooms goes, it never seemed to do much for me. Not unless I hadn't eaten enough and wasn't shroomin to hard. If I was shroomin really good the shrooms always overpowered the weed so I didn't feel much. Probably depends on the person and shrooms though so give it a try yourself.