Where can i find cute femboys in bkk?

Look in any department store cosmetic department.

Everywhere. The cutest but not necessarily the most approachable femboys can be found on the BTS and in shopping malls.

I've always notice groups of Femboys walking around Nana plaza.

Pattaya.

You'll find plenty at the ladyboy bars in Nanna plaza

Pattaya.

Jomtien complex is swich city.

There are a couple of twinky femboys in Classic Boy. 
Only ones I have really seen working on Soi Twilight. 

If you go to Stranger Bar on Silom Soi 4 (its a drag bar) you will find a few Thai femboys on weekends. I know a couple of them.

There are a couple of twinky femboys in Classic Boy. 

Only ones I have really seen working on Soi Twilight. 

If you go to Stranger Bar on Silom Soi 4 (its a drag bar) you will find a few Thai femboys on weekends. I know a couple of them.

Unfourtunately most truely gay boys in L.O.S. act fem not to be confused with "Ladyboy".

I am not confusing things with Ladyboys mate. In fact when it comes to Classic Boy I dont think any of the drag acts are lady boys. Just drag. My favorite boy in there, arguably their best dancer Tom does drag some nights. Strangely though hes quite manly..

 

As said before a couple of the boys there are very very effeminate. As you said many real gay thai boys are, some however far more than others.