........ """"""""The most important factor in harvest is timing for peak THC production.
in order to do this you must observe the trichomes (or trichs), which is the technical name for the crystally bits that cover your leaves and calyxes (calyxes are the bud bits that the hairs grow out from)
first, (unless you are able to move your plant without risk of damage) select a small side bud and clip it off at the stem. then take it out of the growroom and into natural (but not direct) light. aim for flat but bright light, like sunlight reflected off a white wall.
get your magnifying glass (30X jewelers loupe is good, and only about US$20 off the net) , and have a good look at the trichomes from the side-on observe the colour of the head (cannabinoid secretions) and wait till around 50% of the capitated stalked trichomes have turned colour from clear to milky/amber. this will give the best all round high. """"""""""""""