Snip and Sketch can be found in the Start Menu or by holding Windows Key + Shift and S.

Open and you're presented with a grey window.



You can press 'New' and cutout anything present on the screen behind, which is then saved as an Image in your Pictures folder.
Sometimes you might want to snip something (like a drop-down menu) that disappears when you move the mouse off it, or click away.
To get around this, you can get the Snip and Sketch to hit 'New' automatically on a timer. Just press the little arrow next to New and select 3 or 10 seconds:



The whole screen will go dark and you can simply select the tool from the top bar and draw around what you want to Snip:


Drawing around an object brightens it:



When you let go of the mouse, the Snip is saved I the original Grey window:



Here you can save it, share it, paste in straight to another program (it's automatically copied for you), Sketch over it using the tools at the top, save as PDF/image etc.