Show shots of the vows. You can screw up almost everything else, but the Bride’s entrance, THE VOWS, and the exit are the key.
Well-composed and shot vows shots with great audio will convince the watcher that you know what you’re doing. The audio makes the biggest difference between Uncle Charlie’s on-camera shotgun mic from the tenth row, and your wireless lav on the groom getting every nuance of how she chokes up during her recitation of those vows.
All the other fancy over the top glitz and eye candy and editing tricks you want to show are fine, but really, the hiring bride or their mom’s first question is: “can you really do this job properly”? The bride is running a movie of that vows shot in her head, You can bet your house on it. She is going to want to know if you can make that dream image real, for a fair price.