5. Know what the real towing capacity and towing speed of your vehicle is. I blew out the engine on a 4-cylinder trooper pulling a 1200 lb. boat. The Trooper was rated to pull over 2000 lb. but the engine didn't make it to 60 thousand miles. It was a very expensive lesson.
6. Make your your trailer is suitable for hauling your boat. Boat trailers can make towing easy or hell. The first trailer I had (the one recommended by the dealer) was inadequate for the boat. Subsequently, I had to get rid of it after several expensive and potentially dangerous breakdowns. Even without these major problems it was difficult to get the boat on and off the trailer and it never seemed to ride right behind my car. The replacement I got made all the difference in the world. It pulls easy and loading and unloading are simple.
7. It can be very dangerous pulling a boat behind a improperly equipped vehicle. Just recently on I-95, I saw a little Suzsuki 4X4 pulling a 1500 lb. plus rig. The car was being whipped about by the trailer and the driver didn't have the sense to slow down. I didn't stay around to see whether or not he'd make it to his destination, but that man was a hazard to both himself and all of the other drivers on the road. For serious towing I recommend either a pickup truck or a large utility with a V8 (like a Suburban). All due regards to these cute sport 4X4's with their V6 engines for fuel efficiency, but they don't have the wheel base, weight, or
horsepower to pull around a 2000 lb. plus boat and trailer.
So maybe you've thought about the above. Are you set to go to the showroom. I don't think so. Most of us tend to be rather spontaneous in our decisions to buy. Spend some time contacting boat manufacturers about what they have available in the way of models, construction, and options. Boat shows tend to be good places to see a variety of makes and models, but watch out for the salespeople. Typically, they are not very honest (and in many cases not very knowledgeable). Collect brochures, make notes about what you like and dislike. Ask about pricing. If you get a price write it down and note the name of the salesman. Any price they give you at a show they should be able to repeat after you've had a day or two to think about it. Ask about package deals. Its easier to get all your electronics, biminis, and options financed in one low payment then having to worry about adding on later, but make sure that your getting the quality of equipment that you want.
Now your set to go buy a boat. Contact the dealers that have the brands you want and look them all over then make your best purchase. It might take a little more time to use this approach but in the long run you'll probably end up being a happier boater.