While our antennas are multi directional it helps immeasurably to have the flat face of the antenna pointed in the direction of the towers so that the signals have as much surface to "land on", so to speak, as possible. While the sides of our antennas will pull in signals it's a pretty small area for signals to try and "land". Think of an antenna like a tennis racket. You COULD use the sides of the racket to hit the ball, however you'd have much more success using the webbing as the designer had intended. Same theory applies to antennas.
Many site tools will allow you to enter in your complete address so you can get a general idea of which way to point your antenna. Always use your complete address so that the information is specific to your location. Even a move of a few inches can make a huge difference with reception.
Most cellular phones have a compass app that will allow you to find the exact placement for your antenna.
So what do you do when you have that one signal that is positioned so that you just can't get the flat face of the antenna pointed in a way that will get them all?
Unfortunately, that can be the one downside of using an antenna. When all the signals are coming from one direction with the exception of one the best thing we can suggest is to try several different placements until you find the one spot that yields the best results for your location. In some cases you may not be able to pull in a signal based on the direction it is coming towards you. Finding the "sweet spot" or as close to it as possible is key in obtaining the best reception possible. ALWAYS remember to run your channel scan with EVERY move of the antenna no matter how slight. This is one of the most overlooked instructions that we deal with when customers are setting up their antenna.