Most shots taken in Texas for whitetail are under 200 yards and typically have a fairly good rest (i.e. a deer blind) so most people wont need anything to powerful. That being said a good pair of binoculars comes in extremely hand to identify specific bucks without having to raise your rifl every time you want tot check an animal out.
When it comes to knives and lights I prefer to keep it simple and easy to use. The Outdoor Edge is great because you never have to worry about forgetting a sharpener at home. The headlamp on this list is one of my favorite as it's extremely bright and you can detach the light and use it as a flashlight as well. I just toss it and the rest of my gear in my Mystery Ranch pack and head to the stand.
A good trail camera can save you a lot of time and gas money. Cell cams have come a very long way over the years and reveal seems to have the best quality and bang for the buck (no pun intended). For everyone who is technology impaired it is extremely easy to setup and use.
If you have ever hunted whitetail in Texas you know you can go from teeth chattering cold one morning to sweating the next morning. My biggest key to hunting in any situation is layers, you can take them off as it warms up or add more as the cold front blows in.
These items are for a little added comfort while you are hunting, the socks are nice and warm but wont make your feet sweat if you go walking in them. The gloves I prefer to keep light so I can use my hands easily and when they get cold I use the hand muff to warm them up.