I think it's great if you want to show off your work. I'm looking forward to seeing it.
I really think it's a cool idea to have a contest. But, I don't think the contest should be built around a participant's project. I know that if I were going to be a participant (which I'm not because I'm a manufacturer and not an installer) that I would be a bit skeptical of a contest where the rules are designed toward one participants project.
I think if it's going to be a contest/challenge that it's got to be a level playing field for everyone. I think that only a few ground rules are necessary:
1. All the same substrate and size no matter what that is... I think the size should be something that makes sense for a 3'x5' sheet of tile backerboard. I think that the people that participate may make several tries before picking the one they want to enter in the photograph. So, it might get expensive if the size were 3'x5'. So, if we wanted to do 12"x12" you can get 15 tiles out of a single sheet of backerboard. If 18"x18" then you will get 6 and a bit of scrap. Is 12"x12" big enough?
2. Suitable for a garage... Since this is 'Garage Journal' it probably ought to have something to do with the garage.
3. There should be a limited amount of entries... So, each participant could enter multiple times but not unlimited. I would say... maybe... 5...
4. Let's make it interesting with some CASH for a prize! I think that we would be willing to donate $10 per entrant (person not entry) up to $100 in the form of a gift card... I'm sure that we would NOT do one to Walmart... but... Home Depot... Lowes... Target... ??? Maybe someone else here would want to sweeten the pot too? Winner take all???
5. Since many people don't check the forums that often... shouldn't the submission dates maybe be the whole month of August and then a voting thread to run for 2 weeks the first of September? I think this would get the most participation.
That's about all I can think of right now... I think this is a cool idea... but I think the playing field should be level for all...