1
Hey Doc, just a quick little tip that may or may not improve your current workflow.
If you use the keyboard shortcut "Shift + Command + 4" it will bring up a little crosshair. Drag that over the selection you want to capture (just like Grab), and when you release the mouse, it will save a .png file to your desktop automatically. This way it saves it automatically eliminating a step, and it's not a .tiff, so you don't have to convert it. If you do "Shift + Control + Command + 4", it won't save the image – instead it will just copy it to your clipboard, if you want to paste it somewhere else.
Hopefully that's helpful :)