Casual Friday has become far more confusing than it should be. Specifically, the word "casual" has definitely tripped-up some people. For some, casual equates to sloppy, ultimately implying that gym shorts and flip-flops are a go for work. Let me help you out with this thought, they absolutely are not. Now that we've reached this common place, hopefully you can identify your office type and dress accordingly.
The Strict Office- If your office is mostly populated by the 40+ crowd and wearing a tie throughout the week is expected, this is the section for you. For this office environment, I think its best to keep everything simple and to the point. From personal experience, dressing too "out there" at a more traditional workplace just sets you up to be bothered all day. If it's not questions about your clothes, it's stares. If you don't mind either of those things, then wear what you want. If like me, it would get old real fast, avoid crazy colors and loud pattens. In my opinion, a clean polo and dress pants is the go-to.
The Relaxed Office- If your office falls into this category, you don't really need to follow traditional office dress rules. If you're wanting to wear jeans, I would say lean towards dark-wash. To make jeans look less dressed down, go for a nice button-up. Preferably a solid or subtle pattern. Go for some color. If you're feeling especially brave, you can even try wearing some shorts. I would say think of "Causal Friday" dress the same way you'd think of "going out to dinner with friends" dress.
Remember, the casual in "Casual Friday" does not mean sloppy and/or careless. You don't want to put in all that work to look great all week and then fall off on Friday. It just wouldn't be right.
Thanks for reading,