So as your non negotiables, you want to take:
2 trainers
3 PJs
2 sandals
assorted dresses and shorts/T shirt outfits
is that right?
i would wear the heavier of the trainers, plus your heaviest other items- belt, etc, and jumper if you’re bringing one (useful in air con). If you’re bringing trousers I would wear them; a dress if not.
Get the lightest fabric pjs or nighties you can find, like really light cotton, because it will be so hot (they’ll offer a bit of protection against mosquitoes as well). Then they’ll just roll up and squash in.
If you like bigger knickers, consider taking fewer pairs and hand washing them when you’re in the shower. Stuff them into your trainers in the suitcase.
You can also hand wash light cotton tops. I have a few in Indian block printed cotton and they wash very easily and dry quickly. I just use the shower gel or soap I’ve brought or that the hotel provides and target the underarms. Then a good rinse, shake it out before you hang it up overnight and you have a nice clean top in the morning.
Agree about taking neutral base items (beige, denim, khaki, charcoal, grey, depending on whether your tops are warm or cool colours), and the sudoku method looks great- I haven’t tried it but I’ve seen it and can see it could be useful.
Small items can be what make your wardrobe feel less basic- things like scarves, belts, and jewellery or a stunning item like a silk kimono that layers over all your neutral base items.
have a great time!