Be sure not to put the cooked food back on the same platter that held raw meat. Don't use the same marinade that held raw meat to baste foods during the last 10 minutes of cooking. If you want to continue basting throughout cooking, reserve some marinade ahead of time for that purpose. Avoid using recipes such as homemade ice cream that contain raw eggs, since they carry a risk of salmonella. But if you must, then use eggs that have been pasteurized to kill any harmful bacteria inside.
Pasteurized eggs are now available in some retail grocery stores in the refrigerated section.
Keeping your hands clean in the great outdoors can present a challenge. Plan ahead to make provisions if you will be picnicking in a location where you won't have access to soap and running water. Wash your hands often, especially after handling raw meat. Don't leave food out for people to eat all during the day. Foods should not be keep at room temperature for more than two hours.