Travel sized toiletries, mascara &lipstick, one pair shorts, one maxi skirt, one dress, pashmina that can double up a shoulder cover or a sarong.
Four tops that will work with either shorts or skirt.
Two client weight cardigans
One pair sparkly flip flops. One pair shoes you can walk in (flats or wedges)
Lightweight handbag/beach bag that can be rolled up and squeezed into hand luggage.
Sunglasses, big squashy straw hat (can be packed into hand luggage, stuff the crown with clothes and round the edges)
Bikini/swimsuit.
1 bra (wear the other one), pair of knickers per day.
Kindle or books. Phone charger. Antihistamine tablets. Painkillers.
Buy sun cream when you get there.
Easy. Done!
The key thing is to make sure that everything you take can be worn with everything else, gives you more combinations and stuff can always be quickly hand washed if needed.
You always need less than you think you do, I find the hardest thing is fitting all my books in - I usually end up with a lightweight trench that I can stuff books in the pockets of, or make my DH stick them in his pockets!
Have fun!