So you like the look of your iPhone sans case? Instructables user timwikander has come up with a clever solution using a typical produce elastic band found in a grocery store to help increase your grip on the iPhone without sacrificing slimness and looks.
Simply stretch the elastic around the edges of your phone! In order to maintain the charging port and headphone jack you can try using a tiny drill bit to bore out a few holes as needed to help gain access. This clever idea isn’t limited to iPhones either, you can easily apply this to similarly sized smartphones too.