I often find that inexperienced producers try to make their song sound as loud as possible before they’ve produced a solid mix. But in their defense, it’s difficult to imagine how your song will sound once its mixed and then mastered. So, the instinct is to try and make it sound like the finished product before it’s even mixed.
Just remember this, go for a good clean mix with nicely balanced frequencies and levels and trust that the loudness will come when it’s mastered. In fact, here’s a perfect example of how a song can evolve from the demo (the first 8 bars in the example below), to the final mix (the next 8 bars), and then the master (the last 8 bars). I signed this song, “Funky Jellybeans”, to my label (Synchronized Music) as a demo. Then I mixed it directly in Reason using the artist’s (Soniferous) original session file. After we were happy with the mix, I mastered it in Pro Tools using the Waves Mastering plug-ins. You can hear how the mix goes from loud but muddy, to quite but clear, and then loud and clear. In the SoundCloud thumbnail you can even see the song’s waveform evolve in the three versions (from top to bottom, demo, mix, and master).