Proper antenna aiming can be highly beneficial to the quality of your audio. Omni antennas, such as the whips that are provided with a new wireless microphone, pick up in a 360° horizontal circle, so they cannot be aimed. They provide low gain and no rejection of local interference.
Directional antennas (paddles and helical) provide additional range and typically reject 50% or more of local interference. The horizontal coverage angle of directional antennas is what you need to consider when aiming antennas. Visualize a triangle with the pattern of the antenna and lay that over the floor plan to include every position you need to fully cover your event.
Antenna Placement Webinar
Scanning for Antenna Positioning