In OS X Yosemite, there were some services menu items available when I right-clicked. But I no longer see them after updating to macOS Sierra. How can I get them back?
Go to System Preferences > Keyboard > Shortcuts, then select Services. There you can choose the Services you want. After that, right-click on a folder in Finder should reveal the Services menu.
Note that these actions aren’t available to all items you right-click on. But you can always see some menu actions when right-clicking in Finder.