get a kitchen roll cardboard tube, or toilet roll inner tube and stuff it full of cotton wool and/or tissue paper, then when theres loads in seal one end as best as possible.

use this to exhale your smoke into, this used in conjunction with basic commom sense like: extinguising the bowl after each burn, and having a window open, and smoking near that window.

will mean that there is very little, if any, smoke odours in ya room.