What I have seen people do is try to brig a player making a final attempt to sway someone to help. The best success I have had in a game was grab the admiral position for a turn with a character power, and hit the FTL early. Are there any better strategies? Do you think you should deny it to the bitter end no matter what never taking openly hostile actions?
Most of the absolute best reveals I have seen typically involve either getting an executive order, or playing a critical situation, whilst abusing things like arrest orders. Most recently, we had Laura Roslin, who had moved to the Admiral's Quarters with the intention of visiting the Ally there, receive an Executive Order from another player. Roslin immediately played an arrest order with her first action, brigging that player, and then with her second action, activated the location, targetting another human, and then playing the new 6-strength yellow skill card that auto-passes locational checks in order to force him to the brig as well with no check. That ended the turn of the unfortunate human; next up was... Laura Roslin, who played another arrest order, brigging the last human player, and then revealed as a Cylon (the shock!) damaging Galactica. That particular game ended in a hurry as the two revealed cylons were now opposed by three inmates, and the damage mounted up fast and furious.
NEVER XO the player whose turn is next, unless all cylons are accounted for.
The contrapositive lesson for the cylon:
Get an XO when your turn is soon or next for maximum carnage.
Overall, the key to a successful reveal is to either cripple mankind directly with big stat hits, or to gain an advantage by wrecking their hands/freedom of movement through execution or brigging. Bear in mind that in the Ionian Nebula, the longer any given person is in the brig (or sickbay) the more likely they are to get executed or eliminated in the trial.
Being the Admiral before revealing is definitely the most damaging for the humans. Firing nukes unnecessarily and making one or two really expensive FTL jumps (i.e. low jump distance and high fuel cost) can easily win the game for the Cylons, especially with the latest two expansions. Putting someone in the brig, damaging Galactica, or killing a character is also good (and fun!), but the effects of those are usually temporary.