You have to think about it all the way, from arrangement through tracking and mixing.
To make it simple: You need to use (EQ and) compression
subtly on many tracks, then do a finall compressing/limiting to the finished mix as the final "mastering" move. It's also very good to do manually volume envelopes to even out the biggest jumps in volume, so to make compressors task easier.
If you just throw a limiter in the mixdown track with very strong original dynamics, you will most likely destroy your sound if you aim for "near commercial" loudness.
If your ony option in this case is post mix editing you could try: Volume envelopes> EQ > Compressor > corrective EQ > Limiter.
Izotope Ozone is an excellent mastering tool.
Roey Ishakis book "Mixing Audio" is a good book about these things. It includes a CD with examples of different edits.