Besides getting the correct strain, the very best trick for producing more trichs is to produce a very healthy flowering plant. Use ferts that are geared to growth during veg, and those that are meant for blossoms during 12/12 flower. Give it the best, brightest light you can muster (HPS 400w or better). Some say 48 hours of dark right before harvest helps. Since you're cutting the plants anyway, it probably can't hurt.
Forget all the shortcuts and stress methods that people who never grow throw around. If you have even a few years of solid growing experience you will know that there is no substitute for good plant health. Stress is never good for plants. Very experienced growers sometimes use stress to produce various traits, but in general treat your plants with the best care you can for the best results.
Also remember that trichs do not equal potency, but rather resin. I once grew Dr. Atomic Thai lights which had the most incredible trichs I've ever seen. It was the least potent weed I've ever grown - really shitty - but it looked incredible.
