Some mistakes in my MikroTik configuration

This post seemed like a confession, but I plan it for my future. Maybe readers can take benefit from my experience. Since December 2006 I used MikroTik as router for my cybercafe.
Learn everything from forum and then apply them and customize base on my need. I'm not an IT specialist, and never join any computer/network formal course. I intended to use MikroTik to administer my cybercafe. During my experience with MikroTik, there were so many mistakes I have done in my configuration. Here they are:

1. Doing double NAT (Network Address Translation)

2. Using inappropriate IP (Internet Protocol)
3. Forcing hardware capability
4. Refer to someone's configuration without fully understood about setting function
5. etc

Ok, dude. I will share my experience on next post :)