Whats the next step?

Firstly: The finished mix has to sound reasonably close to the final version. You can't do miracles in the mastering phase. If the mix doesn't sound OK, mastering won't make it "finished".

Do a lot of...or at least some...reading. The Ozone Mastering guide is a quick, good read even if you don't have Izotope Ozone.

At www.tweakheadz.com you'll find guides about everything related to home recording.

Mastering sure isn't something that can be explained shortly, even if we're talking about "mastering". I'm not at all good at it...no guru...just talking :o)

The most basic steps usually include: EQ, Compressor, EQ, Limiter

Mastering was the norm back in the day when all songs were recorded in a tape environment and then send to vinyl. Compression was used to keep the needle from literally jumping out of the groove. Now days mastering after the mixing does not really make sense, because all this can be done during the mixing phase, and as it render to the finished wave file.

AS Kallie, and Beagle said, it takes hard work and practice! Listen to a lot of music of the same type, and sound. Use the same monitor speakers. Mix the tracks as cleanly as possible, be very light handed on effects. Make subtle changes., and do not over compress. Using a good spectrum analyzer on the master bus following a multiband EQ can help keep the song balanced, and keep offensive frequency bands under control. Use a transparent master limiter on the master buss in the last position.   Mix at lower volume levels to avoid ear fatigue, and take breaks so as not to tire of the song. Listen to it on several different systems to see how it translates to different environments.

A clean clear recording that the instruments "sit" well in the mix, that has a decent range of dynamic sounds, and is pleasant to listen to is great.

Lastly on compression, to much will crush the life out of a mix. It presses teh highs down and brings the lows up. This keeps music from having dramatic and dynamic effect. Those sweeping highs after emotional lows.

All good commentary.

Before you master it, the mix has to be right. The level of the instruments, the EQ on the tracks, everything has to be right. One you "master" it, it's done.... adjusting levels at that point is a return to the start.... and go though the whole process again.

I don't really call it mastering..... I call it sweetening the mix.  Mastering refers more to making 10 songs on a CD or album all sound like they were recorded at the same time & place and all at the same level so the listener doesn't have to ride the volume knob on the radio.

I use Ozone to sweeten and finish my work.

The other option is to send it to a Mastering House and let a pro do it for you.  If you're planning a commercial project, this is the preferred route for many.

Ozone is specialized software.   It is generally used as a VST/FX inside of cakewalk.... It will run fine in MC.

I add it in the FX bin generally in the master bus. But I have been know to add it to a track to use just the eq in it.

Can you get a good mix without it? Yes.  All it is, is basically the same type of plug ins that come in MC in the cake audio FX... compressor, EQ, limiter, reverb....

Yes, it is generally used AFTER all recording is done. Track your individual tracks dry. Then add your audio fx after you have the song sounding as good as you can get it before the FX.   If you allow the FX to influence the track's inputted sound, you are stuck with that sound...carved in stone. But if you record it dry you can change the FX until you get the right one.

To get a good sound out if it (ozone) you need to understand what it's doing...same as using the seperate cake plugs..... if not it easy to overdo it..... to you it might sound good, but to someone who knows mixing, production, and music, it will stand out as an amateur mix.

On the other hand, I do use EQ and compression on the input. Herb and I use the same model of interface and it comes with effects. I just use the presets, since I have yet to get into the black science of tweaking the the EQ and compressor.