The best way is to remove the front wheel and place it along side the rear wheel, THEN lock the U-bolt around both wheels AND the rear stays then to a post. Yes, I know, you might have to buy another U-bolt that has a longer U then yours if you can't get it to fit; but this will give you an excuse to get the NY 3000 U-Bolt from Kryptonite.
Then use the thickest cable you can find as a secondary hassle. Personally I don't cable locks because their too easy to cut, but OnGuard makes a really tough armored cable lock called the Rottweiler 5023 (L at end if you need a longer cable) that is 1.2 inches thick with a steel armored plating covering the cable.
The Krypt Fahgettaboudit Chain is even better but the dang thing weighs a ton! OK, not a ton just 5 pounds.
Actually the best way to lock a good bike is to lock it in your house and take a Goodwill or garage sale cheap beater out in the public parking areas.