For what it is worth I make sure that I always smoke at an average pit temperature of 250 degrees, more or less. I watch my temps but if they spike, up or down, I do not worry too much as long as it is not for a prolonged time.
I subscribe to the "if your looking your not cooking" ideology but I am trying to learn how to cook over an open fire, before all the different smokers and accessories we have now that make it easier. I figure if my grandfather could cook without a smoker and Maverick; I should be able to at least match his success with all the stuff I have.
When my
Thermopop slides in and out easy and internal temp is 197-200 I pull it; wrap in foil with AU JUS if you have it, a towel, and put in a cooler to rest for two hours.
IMHO the finished internal temperature is not as important as the tenderness test with the temperature probe.
As to meat selection I use cryovac briskets and use the shake method to figure out which brisket I want( hold meat vertical, centered on the edges and shake to see how much the brisket flexes. Ability to flex is suppose to have something to do with fat content; too much fat and it will be stiff as a board.
I use different woods but prefer mesquite and pecan.
I tried fat side up and down and have good results both ways. Seasoning is basic SPOG. Keep notes.
When I was first smoking briskets I would try to keep everything the same and only change one or two things a cook.
I have had a lot of different pits over the years and some leaked badly and needed mods, others worked fine. I am presently using an Old Smokey and have had better success than I expected. It is great for families with small yards and is portable enough to go to the park, camping, or beach. I did love my Weber bullet smoker but it moved on to my Daughter and Son-in Law's house.
Don't give up, it could take a while. Most smokes of any kind are meant to make the family happy so find what y'all like best.
Let us know how you do and be happy with smoking. Don't let it beat you up. I still get a tough brisket now and then, so I do what any Texan does; have another cold one, cube the meat and make Chile or stew and cornbread or both.
Sorry about the book