A couple of days ago, Tim Kirk posted a very interesting video blog on game design on his YouTube channel. In the about 13 minutes long video he gives great advice to anyone who is considering to design their own roleplaying games.
httpv://www.youtube.com/watch?v=mU5to6zv0-E
I also highly recommend to check out his other videos and his company website.
Stargazer
Michael Wolf is a German games designer and enthusiast best known for his English language role-playing games blog, Stargazer's World, and for creating the free rules-light medieval fantasy adventure game Warrior, Rogue & Mage. He has also worked as an English translator on the German-language Dungeonslayers role-playing game and was part of its editorial team. In addition to his work on Warrior, Rogue & Mage and Dungeonslayers, he has created several self-published games and also performed layout services and published other independent role-playing games such as A Wanderer's Romance, Badass, and the Wyrm System derivative Resolute, Adventurer & Genius, all released through his imprint Stargazer Games. Professionally, he works as a video technician and information technologies specialist. Stargazer's World was started by Michael in August 2008.