plants have the ability to triple in size too, just so ya know. i put my plants into flowering at 11", and now theyre all around 4' tall, lol. If you wanna see some decent LST that isnt following any specific pattern, click the top journal in my sig, and look at the first grow in it. I started tying the plant down when i went into flower. When i put them into flower they were 8" tall, and if i hadnt LSTd them they woulda probably turned out around 2 feet, but i ended up with 11" plants due to the tying down. I did it aggressive though, lol. I ended up with a 1/2 oz from my 2nd plant, and about the same from the 1st, only i harvested way way premature due to a nutrient problem that was killing my plants.
As far as flowering your plant at 6", thats fine, contrary to a couple different posts in here, it wont affect potency, only yield. Youll do just fine though if your just looking to grow a small but decent size sack of personal to see if its worth growing on a more permanent basis. Theres alot of journals you can follow to look as a point of reference, i was just pointin u in my direction because i had some really good success with it.
good luck with your grow dude. wish you all the success in the world. Dont listen to the naysayers, you can flower a plant any time you want within reason man, and your bud will still be potent as its supposed to be, the yield will just be smaller.
Another method you could try is to use a small container. Some people grow their plants in a 20oz cup and veg their plants for 4 weeks in the cups and then flower, and they end up with very small compact plants, that basically turn into one giant bud rather than a plant with buds on it, lol. Theres a shitload of things you can try man, the fun part is experimenting and finding out which way works best for you