Don't be bashful! If you want comments, give comments. You don't need to be an expert photographer to express your opinion about the work of others. You don't need to go into great depth. A simple remark about cropping, composition, color, subject matter, etc. can be of just as much help to a budding photographer as an in-depth critique.
Next to people, landscape and travel rank among the most popular photographic subjects. But as evidenced by many people’s vacation pictures, it isn’t easy to shoot a great travel image. The challenge is how to capture the essence of a travel destination and the feeling that goes with it. The essence of a great scenic image is to zero in on--and convey--what grabbed you about the scene in the first place.