a strong hq unit with survivability(theres no point in havin it if it dies in the first turn!) some core troops, preferably with heavy weapons(missile launchers are good caus they work against tanks and troops. Then expand with a leman russ(standard) to give you some ordnance(whats an IG army without ordnance weapons?) add a basilisk, a salamander(for capturing table quarters in the last turn. Next add some elites or troops, expand like that. HQ-Troops-Heavy-Fast-Elite-repeat. Well, thats my advice.