Good way to bind chest for cosplay without covering shoulder(s)?

Okay, so when I bind, I usually wear a regular sports bra and then I put on a sports bra one size smaller than my usual size and I put it on backwards and pin down the part that goes up onto my throat. This works really well and gets me just about as flat as I can get.

However, I plan on doing a cosplay for a meetup in a week where I'm wearing an XL shirt (er, I'm a medium, so the neck hole with sag on my shoulder) and it'll show part of my shoulder, so I can't do my normal sports bra method, since that goes around my shoulders near my neck.

I know ACE bandages and duct tape are bad and I really don't have time or money to get one of those fancy flattening shirts things, so that's not an option. Idealistically, I'd like to keep both shoulders bare, at least a fair distance around the neck, but if your method only bares one shoulder, then that's fine, I can deal with it.

Any suggestions?

(I'm a C, so it's not too hard to bind, but it's still a little tough)

Please and thank you!!