What is the recommended actionable tip for shopping to maintain a corn-free status, according to the guide?

Adopt a "three-strike" rule regarding the first three ingredients.

Given the pervasive nature of hidden corn derivatives in packaged foods, a practical, time-saving strategy is suggested for grocery shopping aimed at strict avoidance. This actionable tip is the adoption of a "three-strike" rule. When selecting an item, the shopper should immediately examine the ingredient list and if any corn-derived ingredients, such as maltodextrin or dextrose, appear within the first three components listed, the item should be immediately placed back on the shelf without further inspection of the label. This rule efficiently directs the consumer toward whole, less-processed foods, which are inherently less likely to contain those hidden fillers and processing additives often found near the top of ingredient lists.