Best way to harvest herbs & seeds?

Been gardening for three years and haven't really taken winter gardening seriously. I've got beds full of Tulsi and some perennial herbs I need to harvest... I'm wondering what is the best way to harvest herbs in considering seed maturity on the plant. Should I pluck the leaves and let the seeds dry out on the plant in the ground? Can I just pull up the plant and let it all dry out of the ground? Does it matter?

Harvesting these to hopefully start producing Tulsi tea for my local market, amongst other things.

Also, what time of day should this be done?

Thanks for your input.

For harvesting leaves, mid-morning is usually considered best.

You want to wait late enough for the dew to dry, and allow the warmth to draw the essential oils into the leaf.
If you wait too long, the photosynthesis and heat will begin exuding these oils, which can cause them to either evaporate, or turn bitter on the leaves surface. Mid-day is too late for maximum potency, and optimal flavor.

For harvesting seeds, you want them to mature (but not shatter) on the plant if possible. With annuals, if you expect poor weather before the seeds are fully mature, you can pull the whole plant up (saving as much root as possible), and hang it upside down over a tray in a warm, dry place, allowing the seeds to further mature, andfall into the tray.