If you are going to be working as a professional barista (or as a professional anything), here are some words of advice that you should heed above all else: “What is crucial to your success is your ability to get along with your customers, your co-workers, and your managers. Having outstanding technical skills will not bring outstanding success. Having outstanding interpersonal skills is even more important.”
Above all, cleanliness is essential, especially in a food-service business, but also in any business in which you come into close contact with others. Keeping yourself and your clothes clean makes three important statements to your customers and co-workers. First, it shows that you respect yourself. (And if you don’t respect yourself, then why should they?)
Second, it shows that you are considerate of them. If you show up dirty and smelly, your grime and “aroma” will intrude on others’ general enjoyment of the atmosphere in your shop. This is inconsiderate and discourteous. Take a shower before coming to work, and wear clean clothes and clean footwear.
And third, keeping clean makes the statement that you value cleanliness in general and hence in your work. When you are preparing drinks for other people, they want to be able to assume that everything about the preparation of their drinks is 100% sanitary.
You can put out a beautiful latte, but if the customer suspects that it is unsanitary in any way, they will not want to drink it. If it is obvious that you don’t take your personal hygiene seriously, then it is not a great leap to assume that you might not be careful about cleanliness when you prepare their drinks either. So cleanliness is mandatory.