Scratch

This applies to almost any category, but is targeted on Show and Tell.

The Name of a Topic
The name is the most important thing, as it is the first thing people see.
Don't make it some thing like CLICK THIS OR DIE!!!!!. Make a really brief description of your game, such as "Two-Player Tank Game", so people know what the topic's about, which in this case, is a tank game.

The Topic
The topic should contain ALL of these things:
1.A Description of The Game
2.A Link to the Game
3.Feedback Questions (optional)
Here's an example of a good topic:

Hello. I have recently created a really cool two player tank game.
In the game, whoever shoots and hits the opponent first wins.
The cool thing about it is, it has six stages, and you can customize your tank.
I worked really hard on this, and love-its and feedback would be appreciated.
If you play and you find any glitches, tell me, and I'll fix them.
Could you please give opinions on the game quality.
Thank you!
Here's the game (link to project)

See?
You need to grab the reader's attention with details.

Hope this helps!