Feedback when done well can be a valuable gift for the receiver.
Providing empty feedback like “it’s bad or I don’t like it, what a piece of junk” does nothing but create animosity instead, point out specifically which parts of the project are lacking and why, then suggest ways for improvement. This approach will be much more valuable for the craftsman and others reading the post.
What if the piece presented truly is bad, the joints are sloppy, the timber is marked, the stain is blotchy, ask yourself where does that woodworkers skill sets lay. Are they beginners, is this their very first woodworking project. Think back at when you were first beginning to work wood and the challenges you faced.
Instead try this: Your work have some way to go, but one thing that will help you out is studying joinery techniques. Here are a few helpful resources that I used when I was first learning.
That way, you don’t necessarily have to critique a specific piece, but point them in the right direction and tell them what to focus on technically that is going to improve their work.
No level of skill makes anyone an authority on someone else’s artistic expression. So he used screws, nails, wooden nails, Japanese woodworkers once upon a time never used nails not because they thought it was a bad idea but because it was too expensive so they developed unbelievable skills of joinery methods as a work around without having to resort to metallic fixtures. So if you do see nails in a project it does not automatically make the project inferior, in fact if one uses cut nails the holding power is far greater than standard modern day nails due to it’s taper. Some like the marks left from a marking gauge o dovetails others find it repulsive. These are own likes and dislikes and we all don’t share the same favouritism.
A recent forum post was asked of me. If one should use BLO over a shellac finish. Even though this is an unconventional method and the results would of been disastrous I didn’t ridicule the poster. I made him aware of the results but still told him to proceed and see the results for himself on scrap of course. How is one supposed to learn anything without understanding the why. You will learn nothing without doing, reading alone without practice and experimentation will not lead to knowledge.
I leave you with this final bit of philosophy my father used to drum into my head often as I was growing up. “We have five fingers not all are equal length” as we are all at different skill levels we cannot expect standards of work to be the same. So remember be kind and offer constructive criticism and give credit where it’s due.