I just assembled a sample goody bag for Miss V's Luau party.
One wrapped Hershey Bar
1 mini hibiscus print beach ball
1 hisbiscus note pad
1 tropical pencil
1 bottle of bubbles
1 hibiscus print fan
2 tropical tattoos (may add another one or two)
2 tropical silly bands (may add another one)
All of the above is from Oriental Trading, except the wrapped Hershey bar. The bags are perfect size. They are 6x6. It had some bad reviews, but you really need to read the description. If you still aren't sure, measure it out on paper to see if it fits your ideal size.
I am also going to throw in some packages of tropical fruit gummy candy.