Maximise Google Ads efficiency and ROAS for ecommerce

Master purchase intent for every search on Google Shopping

This one's harder to implement but can get you the best results.

A combination of campaign priorities and negative keywords can help you funnel purchase intent into different campaigns, and adjust bidding and ROAS accordingly.

Bidding more aggressively for high intent, purchase level searches can help you get your products in front of the customers most likely to purchase your products, and stop you from overspending on low intent, awareness level searches.