I don't know if this will help any but I like putting some rapids action on my rivers when I can. I don't always do it but here are a couple examples linked where if you check them out you might get some ideas of your own. Hope it helps.
Islyander shows some white water on the rivers here and there.
Elechos <-- only place it shows are the falls due north of the Maelstrom at Les Chutes De Thlot.
By the way I like how this is developing and your mountains are looking very good. Keep up the good work.
looks beautiful and very stylistic but those are much closer dimension maps and different style from what I am trying to do. I agree with Seraphine_Harmonium in terms of relevance. Reagardless beautiful work m8! :)