Animals (Bears, Birds, Wildlife, etc.)
Cartoons, movies, superheroes, etc.
Occupational (Fireman, policeman, teacher, nurse, etc.)
Outdoor (Camping, hunting, beach, ocean, etc.)
Patriotic (Flags, military branches, etc.)
Pro/Collegiate sports teams
Seasonal (Spring, summer, fall, winter)
Sports (Baseball, football, basketball, etc.)
Transportation (Cars, motorcycles, trains, etc.)