ive found (and am still finding) that the best way to look natural is to go natural. ive always used fake decor but lately ive been experimenting with real decor. i picked up a few plants a week ago and planted'm in my 10 gallon. i figure ill practice there instead of my 30 main tank. i did some research on plantgeek.net and the forums there and ended up getting low maintenance java ferns and anubias. i wanted java moss too but they didnt hav any. its not hard at all, java'a are very easy no maintenance - i already got my tanks lights on timers. it may be the substrate, but your tank looks very bright, you could easily keep low maintenance plants

i like your setup thus far
edit: ahh i missed where you said you already had plants, oh well, ill leave it up there for anyone else maybe itll inspire someone

. any pics of it now that its filled out? i love before and after shots

i agree river pebbles would look great