User blog comment:Tekkphreke/Shikai and Bankai/@comment-5218928-20131231010709

All the Captains decided to play with their Shikai and figured out new tricks. That's what he meant. They figured that their FIRST release isn't set in stone, nor a power level. Think back to Urahara and all the different abilities he came up with using Benihime. It's the same with Hitsugaya: he probably figured at first that he could just shoot ice with his sword released, but then he trained and figured out he could make ice out of thin air.