@Kim ********
the requirements are different from embassy to embassy. There are the very basic DTV requirements but some embassies request additional documents. Some request many more documents. E.G. the DTV requirement is to have financial proof of 500K baht. Some embassies require 6 months of bank statements as financial proof, some only 3 months, some only need proof that 500k baht equivalent was in the bank at the time of application.
Kuala Lumpur is notoriously difficult. HCMC and Hanoi seem to be the best/easiest to apply from.