Lots of good advice in this quick post on Thoughtbot’s blog. I especially like this:

It’s easy to list all the things you think need changing in the pull-request but gloss over all the good things present. If you see something good, say something good! It’s refreshing to receive positive feedback. I find that even simple things like these can go a long way:

• “I love this method extraction”
• “These tests look great! 🎉”
• “Nice catch on this poorly named method! Thanks for changing it”