Depending what you have . . . . . I would suggest using a digital recorder to record an output from your board. An aux mix might work well if you record more than one channel. If you want one channel recorded , I would use a direct out as close to the input as I could, possibly even directly of an unused output on a wireless mic receiver. If you have a board with an output marked as a "recorder" output, that's fine, it works but is a more "polluted" signal than one from closer to the input.
I would be less inclined to using an analog sound input into a computer/tablet type device. It can be noisy and can have ground loop issues. If you prefer to record directly to a laptop type device, I would suggest using an external USB type interface.