If you take a taxi, you should give directions to the drivers with:
intersection of main roads close to where you are going
main monuments / business / attractions near where you are going
Same as when you ask people for direction. The reason is most people don't know all the name of the small roads, they are too many. Not all taxi drivers have GPS on their phone. But if you are using Grab (our UBER) they will have GPS.
Also, there are a lot of dead-end streets in Chiang Mai, so navigation is not the easiest without a map.
Enjoy your time in Chiang Mai!