After you use all your abilities in a teamfight. Well you don't do much if you are using a classic build. In order to contribute more you do have to do something passively while your team fights.

As Leona you want to engage as often as it is safe the whole game. Normally after you w,e,q,and r you don't do much more. In this case you have some damage and a lot of slows. Play with Carries like Lucian, Kalista and graves that can close range as fast as you can. PLaying with champs like twitch Varus, Ashe and Cait can be annoying as they won't be able to get much damage down after you land a stun. AS for the rest of the team you also want champs that can keep up. In a teamfight I believe you should go in first with w, e and q in order to draw attention and group up the enemy as they attack you or run away. Then you ult. In lane try to execute when your carry is low to heal them and make sure to execute the siege minions for extra gold.