Im growing in the greenhouse (uk), Last year I force flowered 1 of my plants by putting it in a large compost bin to give it total darkness for 12 hours. This year I wanted to force flower 5 plants so earlyer in the year I built a 4ft by 4ft cube frame and covered it with the thick black plastic builders use. I let the plants grow to about 3ft and then started to cover them, I didnt top them/pinch any tips out as the is just enough room in my cube for the 5 plants it wouldnt be able to fit them all if they where any bushyer. I put them in there every day at 6pm and take them out every morning at 6am. I built it into the greenhouse so the plants are right next to it, i only have to move them a few inchs to cover them. they are about 6 weeks into flowering now and the buds are starting to fatten up, the top colas are looking good! il take some pictures and upload them in a bit..........