Well, less lighting within reason.
Most hobbyists who invest in pressurized CO2, high lighting, and the works are usually using MUCH more lighting than what is truly necessary to grow the harder species -- this is a uniquely American phenomenon I feel.
If you check the specifications on several of the top ADA layouts and other Japanese aquaria, they are using far less wpg to create those beautiful aquascapes. Why? They don't care so much about growth rates as much as about plant health and stability. WIth lower lighting levels, the plants are not being "pushed" as hard to grow and are less sensitive to an accidental bottoming out of nutrients if we don't have time or forget or underestimated the amount to fertilize the night before.
Layouts also keep their 'look' for a little longer when lighting isn't so intense, it is easier to turn plants red through nutrient manipulation, etc.
These are some of the things I grew successfully with a single 96w power compact bulb over a 55g (1.75wpg):
Bacopa caroliniana (bright pink, robust)
Hemianthus micranthemoides (very bushy, stems were large)
Ludwigia repens
Hygrophila difformis
Heteranthera zosterifolia (stargrass)
Lobelia cardinalis 'small form'
Anubias barteri var. nana
Limnophila indica
Rotala wallichii
When I ran 2x55w over my 55g (2wpg), I also grew these very well:
Alternanthera reineckii "rosaefolia"
Rotala macrandra
Glossostigma elatinoides (flat carpet!)
Blyxa aubertii
Didiplis diandra
Carlos