Hi there!
I cannot give you any specific recommendations for Thailand, but I can give you some general recommendations that worked very well for me.
1. Find yourself a good singing teacher and work to raise your pitch. This is more a case of doing exercises than singing, but if you like singing too, it's a great way to improve. A good teacher will also show you how to use your diaphragm to breathe and project properly, and this will also give you power in a more female pitch. Give yourself at least a couple of months to note an improvement.
2. Start listening to how women speak, but REALLY listen to how they speak, and how they inflect and phrase their sentences.
3. Find a female radio or TV presenter whose voice you like and which is near to your pitch, record them, and immitate them. Record yourself and listen to yourself. You will soon realise how you speak and how they speak and the differences will be obvious. You then need to practise until it becomes comfortable.
4. Once you've started the first 3 things, ask your friends for some feedback. If your voice already falls close to part of a normal female pitch, you will be pleasantly surprised.
Good luck
Julia
