When i submit my designs (logo, business card, etc) in any contest, it doesn't give sharp look instead of others. My design looks like a little blur while submitting to the contest. I made designs in Adobe Illustrator CS-5. How could i get sharpness in my design so the contest holder could inspire with my creativity?
1) Any "contest" is really a bad idea, always. They do nothing but take advantage of you.
2) If you are uploading images to a web site, web sites have server-side image tools which generally alter the image for size and then re-compress, re-save it. It is traditionally best to upload the size displayed on the web site so that the server tools don't have to resize the image.
I love to join contest site too. Some contest sites has a compression system which saves your file into a smaller format for viewing. But as far as I know the detailed version or the original size of your submitted entry is always available to contest holder.
Just make sure to submit a large or a zoom version of your design. For example: 1200pixel by 1000pixel at 72dpi.
P.S.: I prefer .PNG file format because by default PNG files has no compression and keeps the quality of your design.