I believe it was @vegasphotog who said that when he submits his photos for critique, he only wants the experts to share their thoughts. Otherwise, it’s unhelpful.
I tend to agree with Robert. A great instructor, in any subject matter, can accelerate your learning process. A less than great instructor can cause you to learn things incorrectly and make you a worse practitioner.
Having said that, I know that others may feel differently and might enjoy group feedback on each other’s work.
My thoughts on themed days is a mix of entry level to “this is what you can do with all the right gear and years of experience.”
Phone Photography. Every pic is taken on a smartphone AND edited on a smartphone.
Close up photography. I’ve been loving @JazliAziz ’s explorations with this format.
Black and White Photography. Again, this is more accessible since you don’t have to deal with lighting for color issues.
Action. Things in motion, blur photography.
Nature. Flowers yes, but also chipmunks, marmots and other wildlife.
Buildings. Watch @JeffersonGrahamPhoto ’s photo walks and you’ll see an expert’s finds of interesting shots of architecture and signage. Share your own attempts from travel or wandering around your neighborhood.
Big productions. Multiple light sources, gels, etc.