Great contributions so far guys, I'm amazed at the collective knowledge, and generosity everyone shows for sharing their special techniques.
You have got to try this one tho, it works! Swinging Stress Training (SST) - best for SOG plants in small smart/fabric pots, can be adapted for larger plants/other pots
Swinging Stress Trainiing - the Technique
Pick the pot up by the fabric handles or rim (at 9 and 3 o'clock) and extend your elbows directly down infront of you.
Like ginkgo flower in spring breeze, begin to sway the plant in an arc, gently increasing the amplitude of the swing and accelerating the downswing to force oxygen and auxins down the stem and into the root system.
This is the centripetal force (like a discus, or slingshot thrower) in action. Build up your swing until the plant is nearly reaching vertical above your head at the extremes.
It is best to do this last thing before lights out, when the auxins and sugars have been generated in the meristems and leaves at the top of the plant and need to be transported down to the roots.
The results are impressive, i have found, if repeated daily for a total of 1 minute at full intensity. Other patterns may be even better. Here is a picture of a MASSIVE CAPILLARY root formation on a 2 week old male I killed,