1- Using display network and partner networks by default when setting up a search campaign
Display network is a good fit and the most cost-effective way to retarget past visitors and branding but there's no point using display network at the bottom of the funnel search campaign..also advertising in partner networks may increase traffic and impressions but the quality of these traffic is relatively low so you need to refrain from using these to when setting up a search campaign
2- Disable auto-apply recommendations
You need to take control over your campaigns, not Google. When you turn on auto-apply recommendations you are giving full control to Google for making any changes that google machine learning algorithm thinks right or useful for your campaigns
But the thing is google is not always right, most of the time these recommendations are only beneficial to Google
So make sure you turned off this on settings
3- Dynamic assets
Disable dynamic asset generation for extensions as sometimes the assets generated by Google looking into your website are completely irrelevant to ads and distract users
4-Over budget margins
If you have a campaign that's doing perfectly in 100$ a 100-a-day margin but when you try to increase this budget hoping for more conversions google will try to spend all your budget by increasing CPC's looking for volume, especially with smart bidding
5-incorrectly using broad match
Google is pushing users massively towards using broad matches. Yes, broad match has its own benefits when used correctly but it could not be used as a primary keywords match type. you need to use more focused match types as primary match types. Use 1 or 2 broad match keywords per ad group
6-stop caring about the optimization score
An optimization score is just a score that shows you how closely you are matching what Google tells you to do. The problem here is what Google tells you to do isn't always right. don't be a Google' puppet and flush your ad budget. make decisions based on data and test
7-Ad scheduling
If you aren't running a business that solely relies on phone calls like a call center or something like that you don't need to schedule your ads. Google's bottom-of-funnel demand is always there.
8-Running performance max instead of search campaign
Google always recommends starting a Pmax campaign as your first ad campaign instead of a search..
search ads are at the bottom of the funnel. you need to start with search and then move to other campaign types