One of the truly great things about bowhunting is that it's full of surprises. Despite all your scouting and preparation, every now and then something unexpected happens. It might take the form of a nice, previously unknown buck entering the area. It could be a drastic change in weather or conditions that impacts your comfort or alters deer movement. In either case, it helps to have a preconceived game plan.
In the first case, I find it helpful to have settled in my mind what I am targeting long before I get to the stand. My plan might be something as simple as, "I'll take any mature doe or buck." Or it might be "I'm only going to shoot at that big 8-pointer I saw on the trail camera."
These declarations seem like a simple thing, but I find them very helpful in the field. I can only speak for myself, but when I'm in the field and an animal presents itself for a good shot, I can get impulsive and take a shot at an animal I might have let pass had I not got caught up in the excitement of the moment. Having a definite plan often puts the brakes on this.
Similarly, when it comes to weather, it's nice to have a prepared plan in place. Most bowhunters have different stands to deal with changes in the wind. That's great, but I'm talking more about changes in weather such as when heavy snowfalls or rains surprise you. In that case, my back up plan might be to hunt the cedars when deer will congregate or it might be as simple as setting up a ground blind near my treestand so I can be comfortable hunting for the whole day, especially since animals tend to move around a lot on days like these.
Likewise, hard winds might shift my attention to oak stands since they might be dropping a lot of acorns on those days.
The idea is to use those days when you are not in the field to give some serious thought to what you will do when the unexpected happens. This way, you'll waste less time on those days you can hunt and ultimately be more confident too.
Both of those things ultimately lead to a greater chance of success.