Avoid overcorrecting (a.k.a., protect your friends' digital assets)

Click here to review basic sharing in Google Docs. I covered how to make sure your critique partners can't erase your work. But there's another way to activate the track-changes-style editing. 

(Though I have to confess: I find Microsoft's track changes feature to be more cooperative than Google's suggesting mode. Especially if your critique partners have a neverending list of comments and edits.)

When someone else shares their work with you, they may have used the default setting. That means you'll have Editor privileges, and anything you type will look the same as if it was part of the original text.

Activate Suggestions by using the menu on the top right. Text you type will appear in a different color. Deletions you make will show the strikethrough. In this mode, if you accidentally select-all and delete everything, you don't have to hide from your friend in shame! (but also remember the part where you can view the version history and recover a previous draft.)

And always remember, after making your hundreds of gentle suggestions, tell your writer friend how much you love their writing and can't wait to see the next draft!