What itinerary can my friend follow to avoid immigration hassles while traveling in Thailand and nearby countries?

IF they let her board the plane to come here she'll have no problem with passport control when she stamps in. The main thing they are asking on the RARE occasions they do ask are for proof of 20K baht or the equivalent in cash. I couldn't find any posts on forums where people were asked for proof of onward travel (although it is something they CAN ask for).

I'd also say if her passport isn't littered with back-2-back 30 day visa exempt entries or tourist visas to thailand she'll probably skate right thru. Most all of the people asked for proof of funds (and all of those subsequently denied entry) had extensive histories of living here on back-2-back visa exempt or tourist visa entries.

I think the 30 day visa exempt - on arrival will be fine. I have never been asked for anything when entering Thailand - only when trying to get a visa at consulate. She may have troubles boarding the plane, as they are funny about those things. For onward travel I buy a bus ticket online. She can purchase her Cambodia tickets online. The US airlines did tell me i would have to have proof of onward travel (although honestly dont remember if they asked to me to show it when I was checking in).

Barry Teoh. Nothing to do with immigration at all. It's the airline's boarding requirements.!

Most likely scenario immigration will not ask anything..

Just buy your friend a cheap bus ticket to another country. Send the ticket to her and she’ll be covered should the airline ask. Ticket can then be used, sold or thrown out.

If she’s still in the US she could apply for a double or triple entry tourist visa.

Couldn't she have problems boarding (in the US)? I seem to recall most airlines want to see onward travel if you don't have a visa.

Her plan sounds fine, she shouldnt have any problems entering Thailand then Cambodia/Laos and then returning to Thailand.