I'm currently ready a book called Brackish-Water Fishes (Neale Monks, Ed), mainly because I'm still trying to work out exactly what species my mudskippers are. NM has also written a section on plants for brackish water, so I might give it a go at putting some appropriate live plants in with the little fellas. I tried mangrove seedlings previously (with no success), then air plants (which rotted in the high humidity).
Considering my mixed results with live plants in other tanks, I have no idea if this is going to work, so at some point I may have to learn when to give up.