I work in pro tools, so a PT session file is the preferred delivery format.  If you are in Logic, Ableton, or something else, I can also take raw audio files with the same start point.  If this is the option you choose, please include a tempo marking, and make sure that all mono tracks are stemmed out as mono, and stereo tracks are stereo.  Logic guys often end up sending a needlessly large pile of dual mono files, and one sided stereo tracks.  Other than that, please be sure to print any vocal tuning, effects that define the sound of a track (distortion, flanging, lezlie, lofi , etc), and all MIDI.  Also, please include the latest rough mix that you have been listening to.

If you feel that the song is sitting in a place that I should start from, let me know and then print the stems with all current effects/levels/panning so that I have that mix when the faders are set at zero. Also inform me of what was on the mix buss. 

For delivery you can use whatever method you like, or use my Hightail uplink: