When you are ready to export your mix for stereo mastering follow these rules:
Turn off any limiters, maximizers, compressors, stereo wideners that are on the main stereo output channel of your DAW. Please leave all your other processing as it is on your individual channels as this is how you have created your sound. Your track might sound different but let us do the work on it to bring it to the professional standard.
Turn the output volume down so the track does not clip anywhere throughout the track. It is best to use a gain utility for this rather than the fader itself (scientific stuff). Preferably have it peaking at a maximum at -3db, but as long as it does not clip it will be fine.
If you do not do any of the above it can affect the outcome of the master and may not be as good as we could get it.
Export/bounce it out as a 24bit 44.1khz WAV file. 16bit is fine but it will have less information in it which means 24bit is obviously better.
One of the best transfer companies to use is called www.wetransfer.com as it does not get lost in our spam folders. Use to send your files.
We will then create you a masterpiece .. hopefully .. ;)
Any questions just ask.