Cmd-Shift-5 for some more nice screenshot options, including disabling that floating window that appears before your screenshot gets saved to the Desktop
⌘-Shift-5 to disable that floating screen shot thing... I love you. That thing is _so slow_ and distracting I always worry my screen shot didn't actually save until that slow window popped up on some random screen.
I used to hate the screenshot preview, but then discovered I could drag it into applications and websites, or into the trash if it was a mistake.
Or double click for some quick editing and annotation.
You can even have it automatically open on an iPad to annotate on– I cannot overstate how useful this is when you're trying to write instructions for something.
Also, with the preview in the foreground, Command-C will copy the screenshot to the clipboard (e.g., before putting it into the trash).