How can a Vietnamese passport holder maximize their stay in Thailand on a tourist visa?

For a Vietnamese Citizen to obtain a METV...

"Applicants of Multiple-Entry Tourist Visa are required to submit the following documents;

Letter of Employment

Evidence of accommodation booking

Evidence of adequate finance: at least 200,000 THB/ 5,700 USD per person (6 months financial statement) or 400,000 THB/ 11,400 USD per family

Multiple-Entry Tourist Visa will only be granted to Vietnamese passport holders or Vietnamese Temporary/ Permanent Resident Card holders.

Consular officers reserve the rights to request additional documents as deemed necessary"

-Tourist-Visa.html

I have never seen a Vietnamese with a METV, but it is possible. If teh person plan to do visa runs for 30days, please be aware that Vietnamese are not unlimited anymore, just TWICE in a calendar year and for visa application the Vietnamese have to return to home country.

There are two types of Tourist Visa. The Single Entry Tourist Visa which gives you one time an Admitted to Stay period of 60 days and you can apply once for a 30 day Extension of Stay. Or the Multiple Entry Tourist Visa, this visa gives you also 60 days of stay, than you make a border run to activate a new 60 day period. If you make a border run just before the Valid Until date on the visa you can get almost 270 days of stay out of this visa in sections of 60 days and the last period of 60 days with Extension of Stay of 30 days.