How to post mount flood light security lights
Just about anything you do will look like an eyesore unless you're willing to spend 300 to 400 bucks on a 12 foot light pole and bury it 4'. I have seen people take a 14' 4x4 and bury it 4' and run conduit up to an exterior junction box mounted on the flat surface but those posts have a strong tendency to twist. Check with your power company. They may have an outdoor lighting program that could help you on this.  Think about installing the fixture on one of your walls.