What courses have others used to successfully obtain a Thai education visa (DT visa)?

My experience of getting the DTV is they are more concerned about being able to show the 500k thb requirement than the reason for getting it. Also i had to apply using the evisa system; basically if you don't have all the right docs they don't refuse straight away instead telling you what is missing and giving you time to submit all the right docs. Thus if they are not happy with the docs for the course, etc, you can try another course, etc.

Isn’t there a multi entry tourist visa?

Why don't you get a TR visa after 3 month you can go to another country, because it's a visa and not a visa excempt you can do it again and there is no problem

Learn about Thai herbs, 1hr Skype once a month for 5 years. They provide all the paperwork for the DTV. 9999 baht. The company has posted links in previous threads. Or your looking at dental/ medical treatments. There is even an option for attending Thai festivals but I haven’t seen anyone apply in this soft power category.

Why not apply for a 60-day tourist visa at an overseas, embassy.. then look to extend it by 30-days in-country.. which gives you 90-days in Thailand.. then leave for a period before looking to repeat the process.. though an immediate return is not adviseable since immigration might construe it as playing the system to achieve permanent residence.. tourists generally don't stay in Thailand for more than 3-months continuously.. and people that leave for a few days and then try to return are increasingly coming onto immigration's radar.. the message is to get an appropriate visa for your purpose at outset instead of using border bounces to prolong your stay.. and judging by reports this message is getting louder!

I’ve researched two Thai cooking schools 120 hrs 50,000-70,000

Your looking at muay thai or cooking basically

You can obtain an education visa for two things that I know of. One is, to study thai language at an approved school. The other, is to study muay thai. (Thai kickboxing).

It doesn't matter what other people have used. Each embassy sets their own requirements. You need to meet the requirements of the embassy that you will be using.