1. Do not use Banner. Use Text Format :
You see. It looks like content. Place it in the center or front of your content.
728 x 90 Leaderboard : Place it in the top of your page.
Wide Skyscraper Ad (160×600) : Place it in the right-side.
2. No Border.
3. Background. Make your adsense bakground same with your web background.
4. Make adsense links same with color of your web links.