On Macs, there are two great hot-key combinations that can be used for doing screen captures.
- command + shift + 3 = full screen capture
- command + shift + 4 = a partial screen capture based on a box you draw.
By default, when you make a grab with these commands the output files are saved directly to your desktop. If you have a messy desktop, they can be hard to find. Using a little command line magic, you can change this output location to any directory you choose. The command itself is:
defaults write com.apple.screencapture location /output/path/directory
You would just need to change "/output/path/directory" to the location where you want the screen grabs to go.