Wrap items tightly in heavy freezer foil or bags. Make sure your freezer registers 0 degrees or lower. Mayonnaise-based meat, poultry and fish salads don't freeze well. Nor do tomatoes and lettuce. Thawing - Do it the night before Contrary to common practice, it's not safe to thaw meat and poultry on the kitchen counter.
Bacteria can multiply dangerously in the outer layers before inner areas are thawed.
Instead, to allow plenty of time for larger cuts to thaw, take meat or poultry out of the freezer and put it on a refrigerator shelf a night or two before you need it. Small cuts usually will thaw in the refrigerator over night. If meat still is partially frozen when you're ready to leave, no problem. Just cook it a bit longer at the picnic. Cook all meats thoroughly.