[quote=Hank]
Ask Taaj.
[/quote]

Pass out copious amounts of alcohol. Drunkenness encourages creativity in its most raw and natural form.

Encourage method acting- make sure the three people playing the "ghosts of christmas whatever" are thoroughly dead before attempting to embrace their roles. Don't call them by their real names from the day of casting until the curtain closes on the final performance night.

Shove a spike up Scrooge's rectum- it'll give him that uncomfortable sneer/pained grimace he needs. Near the end of the show, dislodge the spike. This will give him that 'freshly re-born" look that's so hard to achieve. 

Create a satanic-sounding chant for the actors to recite before each rehearsal and performance. This will make them feel united.

Encourage sexual relations amongst the cast. It helps to ease tension and won't cause any problems.

Speaking of the cast, make sure to cast the worst actors in each leading role. This will cause them to be under a HUGE amount of pressure and encourage them to improve their acting skills so the more-talented ensemble will be less tempted to assassinate them.

Insist that their lines be memorized in full by the third day of rehearsals. Deprive them of one piece of clothing each time they have to call for a line.

Trust me, I'm a professional.