What size tank
Are you using injected/DIY/Excel
Low Tech= low cost/maintenance
High Tech=high cost/maintenance
If you would like people to suggest more than "buy more plants" then these details
would be helpful. http://www.plantedtank.net/forums/showthread.php?t=107303
Tank - 10g
Substrate - Organic, no soil, potting medium covered with pool filter sand
Lighting - 2 13w spiral CFLs with a diy foil reflector, on a timer
Filter - Aquaclear 20 (diy prefillter)
Fauna - 12 CPDs, 6 RCS (CPDs have been ordered and are awaiting pick up)
DIY Co2 is an option which was already on this tank and could easily be replaced. I also have dry ferts which can be added.
Take a look at my signature, this used to be the "Office utopia" .