1. I usually reserve a room at Wai Ola Vacation resort about 6 months in advance. Then we check tripadvisor and airlines everyday. So its a gamble. We went in Feb, and didnt book our flights until about 30 days before. We found flights drop drastically in December and Jan flying from East coast anyway. It was about 900 bucks round trip but in December the flights went down to 550 dollars round trip. So be diligent and check your airlines web sites every day.
2. If you fly United, its worth the upgrade to economy plus, and in some cases premier travel option too. In premiere you get 2 free bags per person, and economy plus seating which is so much better than coach, a lot more legroom.
3. Remember when leaving Maui, you suitcases are limited to 50lbs, anything over is charged a lot of money. They have a scale at the airport. We usually bring 2 empty duffel bags and whatever cant get us past the weight requirement, we just take on board to avoid the charges.
4. We stayed at Wai Ola and saved a ton rather than staying at expensive hotels. Its up to you but remember some hotels charge fees for things you will never use (tennis courts etc.)
5. We rent from Mauijeeps.com, and get a better rate than any rental car company off the web. If you haven't had a wrangler in Maui on the road to Hana, you're missing out.
6. There's a BBQ place that has live music on Saturday nights, its a local hang out but don't be intimidated, they are awesome people. The guitar player is fantastic, and the owner Johnny, well he get really friendly after a while...it took 2 visits before he smiled at us, but the food was good, the beers were cheap and the people were super! We danced and has a great time. Check my reviews for the name but I think its Smokehouse BBQ...really small and quaint!!
7. I don't care what anyone tells you, Trilogy is the best for any trip you'd like to take, My wife and I have tried just about every other whale watching/snorkel outing and Trilogy is worth the price.
8. We have been to Maui in Feb for the past 3 years so if you have any questions let me know, Ill try to steer you in the right direction.