Before you even create your thread you have to ask yourself these questions:

1. Is there already a similar thread to this? Example 1 and 2

2. Am I asking to trade or begging for something? If so maybe you should check out this sexy site.

3. Is it going to be a puzzle giveaway? Make sure to clearly post that people should not leak your answers, and if they do make sure to report them to support.

4. Is it going to be a controversial topic (religion, ponies, politics, etc)? You should probably not post it.

After you have read these wonderful, wonderful points you may start your thread.

TL;DR Version: Don't Post Anything