You went to Anime North this year!? I did too!
For a photoshoot where you are taking MULTIPLE photos of the same person, manual is suggested. If you're WALKING around to take 2-3 shots of cosplayers, use aperture mode instead. Use an aperture of f/2.8 or whatever is lowest, if you know how to use f/1.8 and below that's better.
I've been to Anime North several times - the photoshoots aren't that great if you want great shots. If you know exactly what you'll be doing you're better off asking some people to the side so specific poses and etc. Because when the host calls out certain "themes" of the photoshoot people tend to pose in poses that make them look horrible on camera or hard to take a good picture. And with a bunch of people there... asking to move just annoys some people off. Especially in a shot with 20 Narutos or something. Just my 2 cents.
By the way try not to crop your photos outside normal ratios like 2:3... it makes it look kinda odd because people are used to seeing photos in 2:3 ratio. ALWAYS SHOOT IN RAW. I cannot emphasize this enough. Editing RAW photos lets you do MUCH MORE than JPG.