Not only you can make tea of fresh thyme, but also you can buy natural thyme extract and follow instructions.

If you know someone that works with herbs and produces natural extracts, even better.

*so agrees about thyme*

imo herbal steams (especially before lying down) are excellent too.

(diy extracts/tinctures are also super easy)

https://www.euphoricherbals.com/blogs/blog/herbs-for-congestion-diy-decongesting-steam

https://theherbalacademy.com/blog/how-to-make-a-tincture/