The challenge with working virtually is how it easy it is to slide into a very casual look! The rule of thumb, especially if you are alone in your office, is to make sure you are dressed appropriately if someone drops in unexpectedly.
The fashion and retail sectors have discovered business casual workout clothes. Uniqlo, Gap, and Crew, to name a few, have made clothing polished with a knit fabric with body shape. Soft jeans in multi-colors besides denim also create a professional look.