Clean UTMs, Trustworthy Reports
UTM parameters are only useful if they are consistent. One campaign spelled two ways, one medium in capitals, or one missing source turns a clean report into a puzzle: the same traffic appears under several labels, and nobody trusts the totals. Auditing the URL before it goes to print is cheap; fixing it afterwards means reprinting.
A naming habit that scales
Agree on lowercase names once — source for the placement, medium for the channel, campaign for the campaign — and reuse them verbatim. Write the convention down where everyone who builds links can find it, and audit every new URL before it ships.