Make a list of trance songs that you would like to play. Part of being a DJ is being able to select songs that would work well together. Make sure that the songs you select will flow well into one another. You can do this by making sure all the songs are roughly the same tempo or BPM (beats per minute).
Beat-match your songs so that they are playing in sync with each other. Playing a new song on top of your current song in order to create a transition is a crucial part of DJing. Preview the song you want to beat-match through your headphones by pressing the "cue" button on your DJ mixer. Use the pitch sliders on your turntables to speed up or slow down the song playing in your headphones so that it matches the BPM of the song that is currently playing. Once it is perfectly matched, use the crossfader to bring in the new song.
Adjust the equalization of your mix using your DJ mixer. An equalizer allows you to cut or boost certain frequencies. If you are combining more than one song together, make sure the frequencies do not clash. Preview the upcoming track in your headphones by pressing the "cue" button on your DJ mixer. You will hear the track, but it won't play through the speakers. Adjust the equalization on the previewed track by turning the equalization knobs so that no one frequency is too overpowering.
Boost the low frequencies slightly. This will allow more of the kick drum to be heard. In trance, the kick drum is one of the driving forces of the song and will encourage the crowd to dance. The harder the kick drum hits, the people will dance. However, make sure the kick drum is not too overpowering: you want to make sure you can still hear the other instruments easily.