Do NOT do the following things in Google Ads during the Christmas period. For text, display, youtube or shopping ads.
Use seasonal adjustments if you are expecting a massive surge. Due to the learning process, it is recommended to change the ROAS at least 2 weeks before the surge.
The more the changes, the more time the campaign takes to learn. Have at least 2 to 3 weeks between each change. Or when the learning has finished.
The review process takes at least 48 hours during busy periods. Also account for policy violations. The most common issue is not having correct titles, which further delays the approval process.
This may lead to overspend if not monitored. Constant maintenance of Google Ads is required to improve your performance.
For example: Don’t plan just for Black Friday but a whole week to 10 days of pre-Christmas sales.