3. Just rent the scooter
When you’re outside of Bangkok, either in the countryside or on an island or otherwise in areas that don’t have a large amount of transportation, from either Tuk-Tuks, taxis or motorcycle taxis, just rent a scooter. It doesn’t cost much and it will make your life so much easier.
This is especially important on islands in Thailand, and I imagine other locales throughout Southeast Asia.
The scooters are not very hard to ride, renting them is cheap and it beats any other form of transportation when you’re outside of the big cities.
The same applies to Vietnam. If you’re not in a densely populated area, rent a scooter.
(They are not that hard to learn to ride).