I use Audacity as a final step even after a Pro Tools mix. I snip the head and tail and adjust the level using the amplify effect, don't forget to check the box to allow clipping, you won't hear distortion.
Will, try this tip to finalize your tracks in Audacity.
Before you trim the beginning, create a slight FADE In from the effects menu.
Repeat on the ending if you are using a fade out.. FADE OUT from the effects menu. This prevents that abrupt jolt from where you go from the silent lead-in into a high volume beginning. The fade-in can be adjusted before trimming so the fade-in is precise enough you still get the feel of a high volume start but not to the point it jolts you out of your seat.
Trim the beginning and end as you normally do.
Select ALL
Effects Menu - select COMPRESSOR
Compress the track but carefully so as to not have any clipping. I normally use 1:5:1
Effects Menu: Select NORMALIZE and normalize the entire song. I normalize to -1db.
Using Audacity, these processes in this order provides all my songs to be consistent with a near equal level when played in a playlist. I get a much better balance to each song because the compressor brings up the overall volume level while lowering the peaks. Amplify just brings everything up.. The normalize after compression usually lowers the track level rather than bringing it up and then balances each song to a consistent level between the other songs on the playlist.
I've found this method effective even on commercially compressed, peaked and limited songs, using slight compression to bring up the overall levels and normalizing down gives me a clear, consistent output without artifacts.