As others have said if you can afford it then a pro company is the way to go otherwise I normally have 3 cubase projects:
- Compose with instruments etc and then export down to stems
- Do the mix on those stems and export as a wav
- Master that wav alone in a project. I tend to use Pro-Q for eq, then a multi band compressor and maybe a touch of reverb and of course a limiter (Pro-L or sometimes Ozone). Often add some saturation to tast, I used to use Ozone for everything but have found I like to mix it up a bit with other plugins but still use Ozone’s maximiser
- Final step is to import into Audition and use that to convert into final formats including dithering etc.