What Diana said.
I do have poison eye and sugar eye and I mostly am not too concerned about that except to not over-accentuate the negative to the point that I don't TRY things in the dressing room or SYC. Experimentation is a great thing and one does not always have to invest any $$ in it.
And avoiding hurtful or dismissive remarks. Including making an effort to find something positive because of the sense of community and not some thumbs -up/thumbs-down concept. And feeling out who wants "feedback" vs. not.
But, I've never quite wrapped up the difference between making what might be "negative" appraisals, meaning, "hmm, I think that should be --(longer, shorter, lighter, darker, more fitted, less fitted) and the idea that that might not be appreciative enough. Meaning, it's either all good all the time (which is true at the ultimate level--fashion and style are not World Peace) or it is not, and I think it would be disingenous to say it is "all good" for fashion itself. That is, "someone" is making judgements about items, proportions, colors, combinations, or there would not be any point in the posts looking for feedback, and so who IS that? Of course opinions can always be put in the context of how it doesn't matter in the big scheme--"I'm wearing my dresses longer these days but that's a personal choice".
So I think "it's all good" maybe should apply to experimenting but not always to the final ensemble! I often have to go "back to the drawing board"!