You can use another launcher which will help some. If you are on well any US carrier you can't get past the bootloader so custom ROMs are not happening, and some carriers you can't even root yet, I think T-Mo (maybe) is the only one you can. The issue is TW is a pig in terms of space and the bloatware apps that Samsung sees as a benefit suck up even more space which is a joke.
Disabling apps doesn't free up space just what is eating up RAM in terms of running in the background. Its an issue and why we want a 32GB VERSION.