Re MarkJ's comments:
In Polynesian cultures, the giving of gifts is kinda obligatory. The islanders, if they get to know you much at all will be giving you stuff. Their cultural expectation is that you will reciprocate, so having things on board that are earmarked for this activity is not just OK (IMO) but needed. In places where one can buy such items from local vendors, Mark's ideas seem good to me, but in many of the areas we have visited in the Pacific islands that option is not available... hence bringing some gift items is helpful.
But the best thing that we've found is to do some helpful act for the village or villagers. I
lost track of the number of outboards I've worked on, sewing machines I've adjusted... things that I may not be highly skilled in, but better able than the locals to do. Once I was able to repair the entire power grid of the village of Solotavui on Kandavu island! This consisted of two small gen sets, one ancient off-brand one with Briggs and Stratton
motor, one shiny new
Honda 2 kw. These were in the big
school on the hill by the village, and the expressions of joy on the
kids faces when they ran was priceless... you see, they powered the only VCR and display on the whole island!
Even better is if you can teach a villager to do some such thing for himself. Not easy to find that opportunity, but rewarding for all if you can.
When we were in the Solomons some years ago, the main source of
income for the villagers was selling
wood carvings. In the more
remote areas, they had little use for cash because there were no stores. They specifically wanted to
trade, and we were advised ahead of time to be supplied with such goods. Second hand clothes, especially for
children, were highly prized. Tools of all sorts, but especially good quality woodcarving tools were also desirable to them (but please, no
cheap Chinese crap! They for sure know the difference!). Rolls of sandpaper in various grits, paste wax and other
wood finishing materials... all good, all appreciated, and not undercutting local vendors.
So, a lot depends on which islands one is visiting. The French islands (French Polynesia and New Caledonia) have more developed infrastructure and a more cash oriented economy than say Tikopia or the Russels. Plan accordingly!
Jim