You probably have a few go-to outfit formulas in your back pocket that make you feel comfortable and ready to take on the world. But a few more in your arsenal wouldn't hurt, right? In fact, after scrolling through Instagram recently, it became clear that there are a plethora of solid outfit ideas out there that are worth adding into the mix. The two common threads throughout the looks in question? They're neither fussy nor difficult to replicate. These are the kind of ensembles that give off an effortless, cool-girl vibe. Here are 17 looks to test out this season. We also shopped out an inspired key piece in each look as well.