Elfman has orchestrators for his scores just like most film composers do. I believe from talking to some players who have worked with him, that he doesn't write and orchestrate in the professional sense. Rather he works within the DAW as all do and passes on the music (midi) to be scored. At least on one recording session, I was told he had a keyboard in the control room and if there was a moment in the score he wasn't happy with, he'd find the notes on the keyboard and tell the team of orchestrators and copyists sitting with him to edit the score...all during the live recording session.
His approach to writing has created some memorable scoring moments for sure. The celesta and female choir in 'Scissorhands' became for a long time, the default brief for Xmas music from advertising companies. I particularly like the main theme to 'Mars Attacks' with its infectious foot-tapping rhythm, quirky vocals and musical nods to the 1950's.
