I'm spending 17 days in Bali in February and for once in my life I want to pack light, particularly as we will be moving around and spending time on other islands.

It will be hot and very humid, with short showers throughout the day. Everyone dresses ultra casual. My hair will be tied back with a head band because it's impossible to maintain my straight bob. I will wear a hat most of the time for sun protection anyway.

How many items would be reasonable? Is there a formula?

I will probably stick to separates apart from one washable silk dress which would be good for nights out.

Advice most welcome.