I've done exactly one trip to Hawaii but I planned it with friends who had been there many times and/or lived there for some significant time.
We went to the Big Island for the variety and to be away from crowds.
Spent 5 nights at a wonderful B&B that I would definitely visit again.
https://www.kaawaloaplantation.com/
It is close to a local beach for snorkeling and some great parks/sites like pu'uhonua o honaunau national park and short drive to Volcanoes national park which was a must see although not sure what the current situation is there.
View from B&B is amazing;
We then went to another B&B for 3 nights that unfortunately is now closed in Honokaa and spent a day or two hiking some amazing beaches and visiting Hilo for a day. The Waipio Valley is amazing and you can easily spend a day there. Rent a Jeep, you'll need it to get to some of the hikes we did.
