I'm pro at smoking without a trace. Yesterday I smoked in my room with both of my parents awake downstairs watching TV.
If you have 2 windows in a room that is the best smoking room because if you leave them cracked while smoking most of the smoke will float out of the window. When you finish smoking open the windows and turn on a fan.
While smoking blow the smoke into a paper towel tube filled with dryer sheets.
When your done smoking take axe and give 5 good sprays. Then get Febreeze and spray any carpet or fabric that smells.
If you let it air out the smell mwill be gone in like 20 minutes. I do this with my parents in the next room over and have never gotten caught in the act.