Business casual attire is a relaxed professional look. For some careers, this may only mean you don't have to wear a belt with your pants or you don't have to wear a collared shirt. It is essentially business attire without the strict policies. However, your company may be more relaxed and allows you to wear a professional look which may consist of wearing a blazer with a pair of dark denim jeans. It all depends on the company dress code. A safe way to obtain this look is to dress in business attire but add your own flair to it. The look I've created above is the perfect example of this. Mint is a soft spring color that is also calming so it is the perfect color to wear to work as you will feel less stressed.
Casual attire is relaxed but it doesn't mean you walk out the house wearing anything you like. You want to avoid excessive cleavage, mini skirts and body con dresses among other things. For some companies, casual attire can be a relaxed business casual look but usually casual means casual. This is where my clients can truly dress for who they are. The best advice for this look is to ask yourself, "would I feel comfortable if my boss saw me in this?"