I found that if you stop and think before you post works well, because what we write may not be interpreted in the manner in which we think. Sometimes I will write a response in a word document, read it, and come back to it a couple of hours later before I post it.
Another strategy I use is to always compliment first and then correct while providing examples. I also use video with audio feedback on assignments. Students are blown away and they say that the video and audio provides a more personal method of feedback, while also demonstrating on their assignments what needs to be corrected and how to do it.
