Good workshopping can vastly improve the writing of both the workshopper and workshoppee. (“Workshopping” just means critiquing or giving feedback on someone’s writing, BTW.) Here are some tips for giving useful, actionable feedback, and giving constructive criticism without being insulting or demotivating! Of course, everyone’s process is different, so go by the expectations of the writer and your critique group as well.

1. Think of what the author wants the story to be, not what you want it to be. This means removing your personal preferences and seeing the story for what it is. Reader responses like “I was confused here” or “I wanted to see more of the worldbuilding” are often helpful, but if the writer is adopting a literary style, for example, critiques like “too much metaphor here” or “I didn’t relate to this style” may not be as helpful. Or maybe you really liked a scene but it was out of character — the author will want to know that it felt out of place so they can fix it, even if you enjoyed it as it was.
2. Be specific. Overall positive feedback like “I enjoyed it!” or “the characters are fun” can be motivating to the author, but are more like compliments than critiques and don’t give much to act on. Make sure to also point to specific examples, e.g. “the use of modern language and the occasional digressions made this dialogue realistic” or “I don’t know these characters’ backstory, so this paragraph confused me.”
3. Give both positive and negative feedback. Unless the author is looking for only one, both are important. Specific positive feedback like “these details set the scene very well” provide motivation, tell the writer what they don’t need to worry about when editing, and give them ideas of what to do more in other scenes. Specific negative feedback (or constructive criticism, or what you didn’t like, or whatever you want to call it) is important to let the author know what didn’t work for you and give them ideas of what to focus on while editing. Be polite and specific, but don’t talk around it. Writers are, in general, brave, intrepid people who are prepared to put their hearts and souls in other people’s hands to be dissected and critiqued. This means it will just be easier for everyone if you get to the point. (Though if a writer is not ready for negative feedback, that’s completely valid too.) Some examples: “I don’t understand this sentence/metaphor,” “this action seems out-of-character,” “(I recommend you) reduce exposition here,” “long words like this pulled me out of the story,” “I wanted more of this character’s thought process here.” Also give the reasons behind your recommendations (e.g. “this decision seemed sudden, so I wanted more of this character’s thought process here” or “we’re focusing on the battle/conversation/revelation here, so I recommend you reduce exposition”). Neutral feedback can also be helpful, e.g. “this scene reminds me of this other book,” “I don’t trust this character,” “you could expand on this aspect of worldbuilding,” “I’m curious about this character’s backstory,” or “though this is a short story, I could see it as the beginning of a novel.” Such commentary can help the writer to see things about their story that they’d missed (which they could then change or build on) and give them more ideas.
4. Give multiple solutions to a problem. Readers will often notice problems writers miss, but writers know the story better than anyone else — which means that they’ll know best what they need to do to fix the problems. Thus, it can be helpful to suggest multiple options; for example, if a character’s action seems sudden and out-of-character, the writer could show backstory that gives them a motivation to do what they did, change the context of the action, have another character do it, or play up other characters’ shock and confusion at the given character’s action.
5. Ask the writer what feedback they’re looking for. This way, you can tailor your feedback to what the author is working on. Specifically, check if they want higher-level feedback, such as on plot points and pacing, or lower-level feedback, such as on grammar (or both!).
6. Know that your feedback will not always be acted on. As I said, the writer knows what’s best for their story, and sometimes your suggestions are not right for the story. That’s not an insult to you or a flaw in your feedback — feedback is helpful even if your suggestions aren’t taken!

If you’re not sure where to start, here are a few of the many questions you can ask yourself when revising your writing or critiquing others’:

1. What did you like and dislike, and why?
2. Were you ever confused?
3. Person and tense: What tense (e.g. past or present) is used, and is the story told linearly or with flashbacks/multiple timelines? Is the tense consistent, and does it ever get confusing? Is the story first-person, limited third-person (one point of view per scene), omniscient third-person (floating between perspectives), or something else? Does that stay consistent throughout? Do the tense and person fit the story’s narration style?
4. Pacing: Does it ever get bogged down in exposition or filler scenes (or any kind of fluff), or rush through important events? Does the pacing of the character development, main plot, and subplots fit the story?
5. Events: Does what happens make sense (and does it need to?)? Is there too little or too much foreshadowing? Do your characters and readers have sufficient reasons to care about what happens?
6. Characters: Are they well-rounded with clear personalities and motivations? Are there specific details about them (habits, clothing/décor, preferences, hobbies, etc.)? How much do we need to know about them given the story’s length? Are there too many or too few characters given the story’s length?
7. Writing style: What is the style, is it consistent, and does it fit the story? Do variations in style convey anything, like different emotions or points of view? Is there sufficient concrete description? (If a later draft: Are there typos or parts that didn’t read well, or parts that were written especially well?)