Buzzwords are fun, but only so useful. I'd say that we use something along the lines of Agile practices, but I think every company's interpretation of that is different.
For us, there are three main things we try to balance:
1. Fun new features that are smaller (enemies, abilities, and other kinds of content).
2. Fixes and balance tweaks (these individually are usually very fast to implement, leading to giant release notes, but the time adds up and we could do nothing but this if we weren't careful).
3. Larger features that take days or weeks, and don't create excitement short-term, but lead to longer-form wins (multiplayer, intro mission, crests, etc).
The key is to evaluate all these various things and try to fit them into a daily schedule that makes sense and that is attainable, and most importantly to mix them together in a way that maximizes the amount of work done. If I am implementing a certain bugfix or feature, and I remember some other kind of related stuff to that, I'll hit them up while I'm there and get a big time savings.