For an event with a formal dress code, the bow tie deserves attention before the final fitting. Sandro's men's bow ties selection gives you a place to look for the collar detail, with availability varying by style.
A bow tie is a concentrated detail, so it does not need much competition nearby. Once you have chosen the collar treatment, look at the full outfit again and remove anything that distracts from the intended level of formality. Judge its proportions against your shirt and the rest of your formal outfit. If you are weighing up a different approach, the combined ties and bow ties collection lets you consider both directions.