I know one: When I have some text from a website or a document with markup, I always paste it to Notepad++ and copy it again before I put it in a document. This way Word or Powerpoint or something isn't messing with existing formatting or anything(I know there are many options to paste without markup and so on but to me, this is just easiest :-) )

It keeping track of number of words / characters is not bad either ^_^.

I'll remember this if I'm ever on a machine without the option to install Notepad++ or something :)

Personally, I just paste it either to the URL bar or with ctrl+shift+v (Chrome, Chromium) into a text field (thinking browser, writing an email)

ctrl+shift+v doesn't work with Google Hangouts, thought.

I use a neat little utility called Puretext for this.

http://stevemiller.net/puretext/

You've never popped open a text editor and started writing things down? I have a dozen notes scattered all over my hard drive because I do that all the time to capture ideas. For some people, it's quicker and easier to open a tab than to open microsoft word. More stable, too.