I forget almost everything about being a mage in Oblivion - except that destruction is better than in Skyrim, hence the playthrough.

I need tips on building my character. I don't want to do it by trial and error again. I want one start, one playthrough. If I have to restart a character again after dozens of hours I will probably quit.

I want to focus on destruction. Please give me build advice, birthsign, race, etc.