Often auto tune, not as a really obvious thing, or even to correct the intonation, but just as something to make the vocals mesh better with the rest of the song. Trance vocals are often made to sound fairly robotic like this, so don't be afraid of really almost over doing it.

Otherwise, delay, reverb, maybe some flanger, sometimes vocoding and obviously compression and EQ are the most common. usual stuff there...

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New Mix: March 2010 Promo
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