A critique is only worth something if it helps your story become more saleable, and as an added benefit, makes you a better writer. If you have someone critique your work and it doesn’t produce this result, you need to look elsewhere for input.
What you want to see.
A critique should point out problems with structure, vocabulary, and style. It should address obvious technical errors in grammar and punctuation. Positive feedback should be provided for passages that are well done.
A proper critique does more than point out what’s “wrong” or “right” with a manuscript. It offers suggestions, examples and/or resources for you to consider.
Maybe your story doesn’t have a beginning, middle and an end. The critique should point this out and make suggestions – or show examples – about how to remedy the situation.
Perhaps you have written a supporting character who doesn’t further the plot – or disappears without explanation. Suppose you refer to your main character as “Tammy” in the first half of the story and “Tammie” in the second half. Maybe you have written a story that is too long for a picture book. All of these – and more – can be cured and corrected through the critique process.
What you don’t want.
While it is always nice to hear positive comments, a critique that reads like a fan letter is rarely helpful. Of course, a well-written passage should be applauded, but gushing praise throughout is not going to help you tweak the rough spots.
Conversely, a critique that berates you is just as worthless. If the critique only emphasizes the negative, it is more of a reflection of the person writing the critique than you or your manuscript. Don’t take it personally. Go out and find someone who can deliver the goods instead of someone who obviously needs an ego stroke.
A critique that only points out marketing suggestions is also not desired. For example, “The character, Michael, is intriguing. I could see building a whole series around him.” Again, accept kudos for your development of Michael, but unless there is more to the critique than that, you aren’t getting your money’s worth.
The bottom line.
Your manuscript is still your manuscript. A critique is supposed to provide helpful suggestions to get your work in saleable condition. You never have to implement every change provided in a critique. Weigh the comments and act accordingly.
Regardless of the results of the critique, you and your work should always be treated respectfully.

