Obscure advanced muting technique for you to try...
James Hill calls it monostrum (great name for it, he has DETAILED instructions and exercises in "Ukulele X"), Dobro players call it raking, Lou Barlow of Dinosair Jr. (and avant garde solo ukulele player) has an entire bass guitar style based around it.
Strum all or almost all strings hard but mute in such a way that only a single open string or fretted note sounds (you'll be using all the muting techniques you know in both hands). Try simple melodies, try scales, try adding riffs to, from, and into chords...
Once you get it down you end up with a way to get fluid melodic lines that stand out with percussive grit.