If the vocal was last to be added by the engineer to the music, you shouldn’t expect a miracle and audio's rich sound. It’s a norm in the styles like hard rock where the voice is rather an addition to wide and saturated guitar sound whereas it’s definitely a failure for let us say pop ballades! So start exactly with vocals online audio mixing if your purpose is to make it the star of a music, and then throughout the process the other instruments will be “eaten” so that they can create an ideal outline for the voice. And such an approach will of course require minimum efforts of yours.
2. The context is the staff of life
In principle, vocal music mixing is such a process that implies the use of “Solo” button only with the purpose of checking audio and tweaking settings. The basic decisions are always made in the context of overall sound. As soon as the professional engineer solos the processed audio, the understanding of its interoperation with the other music elements gets lost, and it’s the highroad to errors. What in solo mode seemed to be clear improvement, it won’t plainly work out in the context of overall sound. The voice isn’t an exception. Any decisions should be estimated from the perspective of how vocals will sound exactly in the context of the entire music, and only after that you can solo its track in order to control fine moments in professional mixing and mastering services which are just impossible to build out when the other instruments sound simultaneously. Apart from that, the attempts of mix and master music in solo mode are the highroad to unreasonable technical decisions and eventually to dull sounding audio. Otherwise after some hours you will have to start the project from a blank sheet. It’s scarcely to anybody’s liking.