Plumb and Level
It is critical when setting up antennas on a tripod that they are set as true to vertical as possible, and this is accomplished by first leveling your tripod while setting it up.
I keep a small bubble level in my antenna storage bag, and when it comes time to set up any of my antennas, I utilize the level as shown here and in the previous photo.
Just so you know, I also use this bubble level for leveling off my mobile when I plan on operating with my inverted U dipole antenna installed on my push up mast mounted in the receiver of my mobile.
I carry short (1 foot) lengths of 2" X 4" in my mobile that I place under the tires (by driving on to them) where required to make it level.
Click on the photo for a closer look.....