Use block ice and fill every gap.

Pre-chill everything before it goes in. Warm drinks and food melt ice fast, wasting space before you even start. Cold items stay cold longer.

Pack block ice at the bottom — cubes melt and create slush that takes up space. Blocks last longer and let you stack drinks directly on top. Fill dead space with sealed bags of ice or frozen water bottles. They act as both coolant and filler.

Organize by weight and frequency: heavy drinks on bottom, food on top. Keep raw meat sealed in a leakproof container on the very bottom in case of drips. Use small baskets or containers to keep things from shifting.

If you still have gaps, toss in a towel or newspaper. It insulates and prevents rattling. You’re not packing for looks — you’re packing for survival.

A well-packed cooler should have zero empty air pockets.