1. Wait. Lie low.
2. Help the more pro-Iranian Shi'ites against the "national" Shi'a. The one thing that really freaks out Americans is the prospect of the growth of Iranian power in the region. Iran is a much bigger country than Iraq and wields a hell of a lot more power. The Israelis figure Iraq is already fucked for the next three generations and their target is now Iran. So the closer the Shi'ite government moves to Iran, the more the U.S. realizes that it needs Saddam Hussein or another Saddam Hussein back in the saddle.
3. Concentrate the killing on the American soldiers. Ignore the so-called "coalition" troops, and the British - - they'll be gone soon enough. Ignore other Iraqis unless they are a direct and immediate threat. For the U.S., numbers are very important. Especially milestone numbers: the 4,000th, the 5,000th; gotta keep those counters spinning. Speed the day.
4. Remember that you will need allies one day. Remember that the enemy of your enemy is your friend. Iran is the enemy of your enemy. So is Syria. Remember that Jordan, Egypt and Saudi Arabia are not the enemies of your enemy; under their current leadership, they are its friends - - which of course could reverse with some lucky regime changes. Work with the Iranians towards a power-sharing agreement with the Shi'ite south, but remember it's important that the Americans see you as the bulwark against Iranian expansion. Secret diplomacy.
5. Be ready when the Americans leave. Give the new government a chance to cozy up to Iran and make sure that bad things happen to anti-Iranian Shi'ite leaders. Anti-Iranians might just as well be pro-American and probably are. United we stand, divided we fall. America has staked its whole regional policy on that "divided." They make it happen. But YOU stay in the background. For the time being, this is a Shi'ite show.
6. After about two years of Shi'ite "majority rule," an army coup d'etat. Nice idealistic young captain, secular Sunnni, good friend of American ideas and Westernization. He should last about two years max, one is more likely - - just long enough that the new "pro-American" military dictatorship is solidly seated. CIA's happy, the Republocrat fascists are happy, as is their mouthpiece, the MSM. Then the next Saddam makes his move, pushes out the interim schmuck, the "regent" who paved the way for him. If he (the new Saddam) is a nice guy, he'll let the "regent" live. Make him ambassador to France.
7. If you've played your diplomatic cards right, you'll have friendly neighbours in Iran and Turkey and diplomatic relations with your other Sunni neighbours, even the U.S. client states. Now it's up to you and the Turks to take back Iraqi Kurdistan with as little bloodshed as possible. Just remember to keep working on those regional alliances, guys.