What does one pack when going to Thailand and then India?

I live in Auckland, New Zealand, a long way from India.
This city is having a Boobs on Bikes Parade on Wednesday.
Sorry to be so crude, but that's nothing compared to what will
be cruising right down the main street in the middle of the afternoon! Seemingly no modesty. What a contrast!

So, I plan to go to India thinking it is going to be hot and I'll need to cover up a bit. They value modesty! You know, I'm thinking this is the perfect chance to do some shopping . . . there!
If I just buy what I need when I get there, I'll look a bit more the part and less foreign.
Of, I may still be one of the few with curly hair and pale skin.

I'll take two books. Only two books. I'll have to check in with you later to see if I've stuck to that commitment. My journal does not count as a book. A good pen!

I'll take a few basic medications that might come in handy and a personal torch/flashlight.
I'll take some gifts from New Zealand to my hosts. I'll plan for the talks I'll give there and will print out some notes on various issues I may want to review as I go.

I hope to find a cache too, so that means I need to take the GPS. Why didn't I get a smaller one?
And a camera and sensible shoes and sunscreen and . . . .

What would you be sure to take on such a trip? The one to India, not down the main street.