Take a sugar leaf off a top bud and a bottom bud. Put those on a piece of paper and use your scope to check the crystals (trichomes) that way-- not the bud while on the plant.
Some plants have long-stalked trichomes, some have almost no stalks at all. You are looking for what look like either lollipops (long stalked) or balls on the leaves...those are the trichs. They should all be headed- no fingers or spikes-and all of them cloudy, or all cloudy with a few starting to turn amber. If all cloudy- time to flush.. if some are amber- it's a bit late for flush, but an emergency flush will work.
Be sure you only check the TOPS of the leaves, not the underside- there are other kinds of trichs there that you do not take into account in this process!
If you need info on emergency flush- drop me a note!