I wanted to make a quick journal about this since it's kind of a vital part of being an artist, professional or amateur. We all need to know how to take criticism and how to give it, and I believe I know a bit about it, so why not share what I've learned, right?
Bottom line, don't be a Sith lord. Don't deal in absolutes. A comment on a piece of artwork saying "I hate this" or "this is awful" is not constructive, or any piece of real criticism. The same can be said for comments like "I love this!" or "this is awesome!" While that's lovely to hear, it does not contribute much to actual growth (but can be helpful for self esteem, haha).
If one wants to give real criticism or constructive advice, my advice is to take a moment and think about what you like or don't like about a piece. Compare it in your mind to another piece that may have done something better.
For example, if I were giving a quick critique of one of my own pieces, say, this one: