If your Mac menu bar is starting to resemble an icon farm, remember that you can remove items from the menu bar by holding down the Command key and dragging items out of the menu. The icon will disappear into a puff of dust, the same way an icon from the Dock or sidebar disappear.
Some menu icons can’t be removed this way and a command drag won’t do anything. Usually these icons are their own applications, like Flux, DesktopUtility, DayO, etc, and instead need to be quit directly from the menu bar item itself. Spotlight is also stubborn but can be hidden as well, although that’s generally only recommended if you don’t use the Command+Spacebar shortcut for the search service.
On a related note, instead of dragging icons out of the menu bar, items can also be dragged around within the menu bar to rearrange them by holding down the command key.
More and more applications are using menu bar items as placeholders or for easy access to their functions, plus there’s a lot of genuinely useful menu bar items. That’s all fine and dandy but the menu bar can quickly become cluttered and start to resemble a Windows-like disaster if you let things get out of control. My general rule is that if it doesn’t get frequent use, pull it out of the menu, you probably won’t miss it.