Take a Stealth Black Hand with Nuke and a Buggy, then use the Buggy to get to the GDI Refinery and plant the Nuclear Strike Beacon. It works good because not many people use this tactic and you will not see engineers in that area. You can also get to the infantry barracks and plant a beacon. Just rush into GDI base with the Buggy through the Tiberium Refinery. You might lose some health, but you will have enough to defend your beacon. Normally no engineer appears.