First off, build lots of defense. (Bunkers, Turrets, and maybe some Goliaths) Now, build everything you need to create ghosts and Battlecruisers, all the while building some defense. Now, this is where it gets costly. Build about 5 ghosts, all with nuking capability and cloak and lockdown. Also build at least 12 Battlecruisers, all with Yamoto capability. Send in the ghosts. Cloak them and lockdown any unit that is a major threat to the Battlecruisers. (Goliaths, Carriers etc...) If you are facing the Zerg you can skip the lockdown part. Next, nuke every anti-air building. When the anti-airs are gone or you run out of nukes, send in the cruisers. Yamoto every building there is, leaving ground units to the ghosts. If you run out of Yamoto just continue shooting. If the ghosts are killed continue shooting. I know this is long and costly, so here are some tips: Use this strategy only on $$$ maps, use this strategy only if you have an ally (Unless you are the god of StarCraft) THIS MAY SEEM IMPOSSIBLE, BUT TRUST ME, IT WORKS. THIS IS THE REASON I GOT INTO A CLAN!!!

CreepColony's Opinion: All the nuking, lockdown-ing, and yamato gunning will waste a lot of time. If you're playing against a human, he/she won't just sit there and let you do your stuff. So be careful.