You can often get a VISA on arrival upon arrival. Fortunately, this often goes smoothly so arrange this at the airport.
Arrange a SIM card of the relevant country immediately upon arrival. This simplifies the journey as you can easily fall back on, for example, Grab for transport and communicate with hotels. We have not opted for this because being constantly online does not contribute to the experience.
From experience we can report that taxi drivers at airports are often not the most reliable. The most important thing is to take a meter taxi. And often it pays to take a regular taxi just outside the airport. Our favorite way was to arrange WIFI at the airport and order a Grab, so there were no surprises.