I mix using Logic Pro X or Pro Tools. All I need is a set of consolidated/synced WAV or AIFF files per song. I also accept Logic and/or Pro Tools session file as long as the audio files are included with the session file and edits/comps are in place (preferably committed/bounced in place with proper fades).
1) Please deliver consolidated audio tracks starting at an identical moment on the timeline using their original recorded sample rate, bit depth, and mono/stereo file type. Do not "bounce" each track individually via the stereo bus (which results in a stereo file each time). Be sure to use an "export all tracks" type function in your DAW.
2) Please remove all plugins (EQ, compression, distortion, delay, reverb etc) prior to export. If there are tracks that utilize plugins to create a specific sound which you are confident you like and want to maintain in the mix stage, please do. However, I strongly advise that you please send 2 versions for these tracks -- one with the effects printed and one without. Any plugins that have any sort of “noise” built in (hiss, hum, tape sound, etc) I’d please ask you to disable that before delivery.
3) Label audio files as best as possible if you have time -- preferably with prefixes by instrument group (DRM, BASS, GTR, VOX, KEY, etc) so I can drop tracks into my mix template session without having to guess or figure out what's what by listening. Please separate prefixes and track name with an underscore character followed by any numbering if there are layers of the same content. example: DRM_KickIn.wav, GTR_Amp1,wav, VOX_Lead1.wav, VOX_Double2.wav, etc...
4) If the track was recorded to a click/grid, please provide BPM per song. Providing the key of the song is helpful too!
5) If you prefer to send the entire session from your DAW, that is okay too! I can accept files from Logic Pro, Pro Tools, Reaper, and Ableton. Please make sure all editing/comping is done beforehand unless otherwise discussed. In addition to printing tracks with important plugin processing, make sure to also print all software instruments to new audio files within your session if you go this route.
6) Finally, archive all files by song into zip files and send via a dropbox share folder, wetransfer.com, or some other kind of online file transfer site. You can also mail a hard drive if you choose.