Are you trying to motivate your employees? Do you want them to function as a team? One of the ways of doing this is by creating a uniform for them; one which will give them an identity. But, your biggest challenges would be to keep it the uniform from becoming boring.
Designing the Uniform
By its very definition, uniform is something which brings everyone at par. It erases the class distinction as well as the hierarchical levels. Have you ever seen people wearing fashionable clothes that are more of a style statement? You need to be inspired by them while designing an employee uniform. Two important and practical aspects to keep in mind are comfort level and ease of maintenance. Polo shirts for uniform sound like a great idea. One, they take care of the practical aspect and second, they can be customized and embellished to make them different.