The best media kit tool is the one you will keep updated, so pick simple over fancy. A clean one-page kit beats any premium template. Whatever builds that fast is the right tool. The bigger mistake is wrong numbers, not bad design, so get your real engagement rate and your rates straight first. KALO IQ has free calculators for both, then drop those figures into whatever you build the kit in.
Tool matters less than the numbers
Brands read the stats, not the gradient. Nail the figures before the layout.
Pick something you will update
A kit you refresh every quarter beats a gorgeous one that goes stale.
Get the numbers right
Real engagement rate and a clear rate range. This is where most kits lie by accident.
Keep it one page
One page, two or three samples with results, done. Length kills replies.