I setup a 10g with a heater, airstone (more for water circulation than oxygenation) and a Hagen C02 kit. The tank is filled usng 'old' water from my other tanks when I do water changes - bringing in Nitrates. I'm using a 'clip on' desk/reading light with a 'plant bulb' (incandescent) for lighting and no hood. Water evaporation means it has to be topped up once or twice a week so the nitrates keep being replenished as well.
Any plant cuttings, or plants that aren't doing so well in other tanks or plant 'bits' leftover from planting, I put into the 10g.
I have a 6g that has 6 endler/guppy hybrids, about 12 RCS and lots of Nerite snails that I've been 'dumping' plant offcuts etc into and they all seem to come back strong so decided to try with a 10g.