Pull out some of the plants that aren't as large or doing as well that are too close to ones that are larger or healthier. Use what you pull as you would with your other herbal tea plants, dry them or whatever. You want to have a healthy space for the other plants to do their best.
What are you growing? Are they baby seedlings?
Do you want to thin out multiple plants or each single plant themselves?
Teresa you could give away your thinned plants as gifts too. There are some plant exchange groups out there. Maybe in your area to share your bounty.