Two seconds, two metres
That is roughly how long and how far away a shopper looks at a shelf. Whatever the label says has to work from there, before anyone picks it up.
Take it to the shop
We print rough mock-ups on the office printer, wrap them around real bottles and boxes, and put them on the shelf of a shop that sells the category. Then we stand back two metres and squint.
One colour, one word
The labels that win are almost always the simplest ones: one strong colour and one word you can read from the other end of the aisle. Everything else can go on the back.