Okay so I don't know what a schooling show is but for any shows except ODES and Show Jumping I always braid.
Sewing looks soo much neater if you can do it, but banding is a good idea if your not used to sewing as it can be difficult to start with. Also another idea that can look quite smart on some horses is instead of using white tape just to use a little but of white wool. So theres that definition, but its not overpowering.
I would pay someone else to full clip if you can't do it yourself.