Think about these hints to make your images even more attractive:
1. NO TEXTS. Please don't put any texts on photos (copyright, author, date etc). You can put your additional information on comment field. Don't glue it to image. It is not stylish so if there are added texts on photos, those photos will not be selected to exhibition.

2. ADJUST. Adjust your artwork's tones and colors readymade before publishing. Image is very rarely 'ready' for publishing when you download it from your camera. Normally you have to at least adjust levels, sharpening maybe color balancing and contrast.

3. FINALIZE. Finalizing is important. Adding matte (passepartout) is not demanded but as it emphasizes images artistic content, it is highly preferable. It is one relevant part of finalizing. But remember that without matte is better than bad matte.

4. NAME IT. Name is essential part of the artwork. Choose decent name for your image, not the default name from your camera. And you don't have to explain your artwork's content & philosophy on that name either. Choosing name to your artwork is to give just a tiny hint for visitor.