1. Fixing conversion tracking
Not because it adds sales, but because every subsequent decision stops being wrong.
2. Rewriting feed titles
In Shopping the feed is the targeting. This is routinely the highest-return change available in a neglected store.
3. Separating brand
Reveals what the account is actually doing, which usually changes where budget goes.
4. Negatives on spending campaigns
Costs nothing, recovers real money in almost every account we open.
5. Raising budget on capped profitable campaigns
The most obvious and most frequently ignored. Free information from Google that most accounts leave sitting there.
Notice that only one of the five is a bidding change, and it is not in the top three.