When you come across a project that you like, show some love! You can leave a compliment or ask the creator details about their work in the comments section.
If someone leaves a comment or asks a question on your project, you can reply by commenting on the thread. The user who left the comment will be notified of your response.
Turning Off Comments
If you wish to disable comments on your entry, you can do so in the edit project screen under the Privacy Options.