first of all, I downloaded garmin basecamp (free download) and found out that it is just so easy to create a route, download it to the unit and the you are ready to go. After you have done the route you can even load you triplog back into basecamp and modify the route using that info - or simply create another route from it. I can only recomend those who have interest in this to download and try for yourselves. The only thing you need (except from basecamp) is a garmin map which can be either onyou garmin device or on a USB stick (also quite easy to find and download if you don't have it).
The big difference between creating a route and just giving a GPS a position to go to is that when you create a route you decide which way you ant to go to get to the position.
When you have created thea route it is also easy to share it with others - either using the same online account (free) or by uploading it to the garmin website as an "garmin adventure" as they call it.
I tried to make three routes (using data from triplogs from my phone), and it only took about 10 minutes each.
Murphys - Dolphin Bay - Sam Roi Yot - Murphys

Northern Loop - Kaeng Krachan

Murphys - Prachuap / Ao Manao - Pranburi Dam - Murphys

Hilux