Like most Android manufacturers, Samsung's TouchWiz UI isn't exactly conservative when it comes to icon usage in your notification bar. While this may not be a problem for some folks, there's nothing wrong with wanting most of the notification bar to be available for, you know, notifications. By the time you've turned on Bluetooth, NFC, set an alarm, and enabled priority notifications, you're using well over half of the bar for persistent things that aren't incoming notifications. One of the big ways you can take some of that space back for yourself is removing the battery percentage indicator on your Galaxy S6, which is pretty simple to do if you know where to look.
You'll turn off the percentage indicator in one of two places in the Battery section of the settings. For some phones (Verizon in particular) you might see it front and center. For others, it'll be hidden behind the "More" overflow menu. To turn this feature off, just uncheck the box. You'll be left with just the battery icon to let you know how much juice you need to get through the day, but gain a ton of space back in the notification tray as a result.
The only place this toggle switch does not apply is in Samsung's Ultra Power Save Mode. Since this is a custom battery saving mode that changes the UI and focuses on keeping the phone alive and partially functional, Samsung takes a lot of control away from the user. Even if you've turned the battery percentage off in normal usage modes, you'll see it re-appear in Ultra Power Save Mode. As soon as you turn this mode off, however, you'll see your settings return to normal.
Like we said, pretty simple as long as you know where to look. Now you can either reclaim some of that precious notification real estate or keep an eye on whether you need to top off the battery before heading out for a night on the town.