One terrific way to bring a bit of Hawaii into your room is to get a large-scale painting or photograph of the islands to hang in your home. You might not be able to see the beach through your window but a huge beach photo can make you feel as if you're almost actually there.
Bringing plants into your home is another terrific way to prolong the feeling that summer is still here. Bathrooms are a great place for tropical plants since they stay moist but you can add plants to any part of your home.
Part of the fun of going to Hawaii is that you get to do adventurous things like zipline rides and kayaking. If you're in the mood to do something daring in your home then a decorative zipline or something of that nature could make you feel inspired inside the comfort of your own space.
A more traditional way that you can capture the heart of Hawaii is to set up an outdoor seating area overlooking a pool. If you don't already have a pool then this would be a major renovation but it's worth the cost to many people since it brings Hawaii right into your backyard.
Any pool at all is a good way to feel like you're on vacation. You don't need anything fancy. A simple rectangular pool will do. Of course, if you can add some palm trees to the yard then it would really feel like Hawaii but that's just a bonus.
Even without a pool, a great little outdoor setup can inspire you to feel like summer is still around. Before the nights get too cool this can be a great place to relax in the evening.
There are two things here that really say "Hawaiian vacation". The first is the fact that so much light is being let into the room. That's a trait of sunny places like Hawaii. The second is the bit of palm tree decor that you see here. It's not elaborate; just simple and perfect.
A great skylight is another good way to bring some sunshne into your home. Try to find a spot in the home where it will let in the most light so you can get the sense that you're in a sunnier destination.
As far as textures and materials go, bamboo is probably your best bet if you want to feel like there's a bit of Hawaii in your home. Whether it's a bamboo plant or bamboo carpeting this is a great way to bring some of the islands home with you.