Do's:

Be a part of the action at Maho Beach.
Have a beach day at Mullet Bay.
Go topless at Orient Bay.
Hike to the highest point on the island, Paradise Peak.
Zipline at Loterie Farm.
Go out in Simpson Bay or Marigot
Make your accommodation on the Dutch side.

Don't:

Mention the division of the island. Yes, the island is half French and half Dutch in regards to ownership, but the people there prefer unification over separation.
Expect places to get lively before 11:30pm. The party starts late on this island.
Be surprised by the traffic, especially in the morning and late afternoon. Also, be very cautious driving!

I. Love. The. Caribbean.

Landing in St. Maarten, you get an aerial view of the blue crystal water you'll experience while you're there. Not to mention the crowds that line up to watch planes land and take off. Arriving at this airport is easy breezy, and catching a cab is made simple as well. My friend and I tend to have honeymoon trips every now and then, so we stayed at the Westin in Dawn Beach on the east side of the island. A cab here should not cost you more than $35, unless you have more than 2 people in your group. Luckily, when my friend got a ride to the hotel, her driver was an informative Belgian guy who was around our age. He ended up being our saving grace during the trip and our new friend. Since we arrived later in the day, we took in the last minutes of sun before heading in to grab some dinner.

The following day was very eventful. First stop: Maho Beach. This is the most touristic area on the island. You should really go for a bit though. When there aren't massive amounts of people from the cruise ships, Sunset Beach Bar can be quite enjoyable and it's a good place to watch the planes fly in, otherwise it's overcrowded. My friend and I decided to be front and center for the show however. We were told not to stand on the sand to prevent being blasted by it. What we weren't prepared for was the blast of wind we were about to experience from the plane. Waving to the pilots of the large American Airlines flight headed to Miami, we looked to our left and noticed people gripping the fence. The guy next to me then said "Good luck" in which I replied, "Good luck for what?" The intensity of the hot air coming from the plane in front of me was enough to almost take me off my feet. If I wasn't holding on to the fence I would have 100% blown away. It was exhilarating in the weirdest way possible.

After our little adrenaline rush, we walked over to Mullet Bay, a decent 10 minute walk from Maho Beach. This beach is beautiful! I would recommend spending a day here. If there are any waves, it will be at the rocks all the way to the left of the beach. Mostly ideal for body surfing, but there are some rideable sets on a good day. Patience is key.

Our last day was spent at our hotel on Dawn Beach, taking in the sun and sea. With all the traffic on the island, it was nice to stay put for the day. At night we made our way back to Simpson Bay and went to a bar called the Soggy Dollar. I personally had a great night, but if you're looking for a more fancy establishment, I may not be your best source of information. Maybe try the bars in Marigot or the Maho area.