The Old Way
I remember, not so long ago, seeing people take screenshots like this:
- Get screen ready with the content to be "screenshot"
- Press the PrtScn button, or Alt and PrtScn
- Open MS Paint
- Paste the copied image
- Edit/Crop the image
- Save or copy the image
- Insert or paste the image into the required application
A better way
Keyboard shortcuts and knowledge of the Snip & Sketch tool make a big difference!
(Oh, I also use an application called Greenshot for taking instant screenshots of my screen, window or an area and automatically saving them as a file to a Screenshots folder. Check it out.)