Brisket is gonna be one of the more difficult items to smoke. Like
@MICHI-CAN said, wrap that bad boy up the last 4-6 hours. Been a while since I've cooked a brisket, I usually go with a pork shoulder or beef roast.
I prefer a roast over a brisket due to price and ease of cooking. You get a very similar product in the end.
If you have any bacon, drape it over the brisket while smoking to keep it moist and add a little flavor.
Here's my recipe for a simple BBQ sauce for basting or dipping.
Ketchup: 1 Big Bottle (4 cups)
Worcestershire: 1 cup to start, add to taste
1/4 cup minced garlic
1/2 cup finely chopped onion
1/2 cup orange juice
1/4 cup spicy mustard
1/2 cup honey ***
2 tbsp smoked paprika
1 tsp cayenne pepper
Salt and Pepper to taste
***Replace the honey with brown sugar, molasses, pineapple or peach preserves, or whatever sweet you want. This base works good with a lot of different flavors. You can play around with it and adjust to your liking. Make sure the Worcestershire you get is made with anchovies, the cheap stuff uses something else. Also I'd add it about 1/4 cup at a time, and taste after thoroughly mixing each time. When your getting close to what you like, just start adding a tbsp at a time until get where you want, its easy to overdo it. If you want to get real fancy, add some finely chopped bacon. I like to adjust the spiciness to the sweet, about 40% spice to 60% sweet, but its all to your taste. Good luck, its looking good!!