The Pha Dok Sieo Nature Trail is a 2-hour scenic nature trail in Doi Inthanon National Park leading past waterfalls, rice patties and all the way to a local Karen village where you get to try coffee and tea from their surrounding plantations. You’ll need a local Karen guide for 200 baht per group (compulsory) but the income goes straight to the village. All you need to do is just show up to the trailhead and local guides will be there waiting to take you.
At the end of the hike they will offer to take you back to the trailhead in a pickup truck for 150 baht extra, which is to be honest quite a rip-off since it turns out the trailhead was only a 5 minute drive away, however riding at the back off the pickup truck was quite fun. Pretty sure you could just walk back along the road instead though!
*Part of Doi Inthanon National Park - entry ticket for the whole national park is needed to access*