Now that guard impacts require a full soul meter to perform, their utility seems to have flown out the window. They aren't even improved from in the previous games, where through them out was completely free.
Guard Impacts were a big part of my game, and now I am having trouble figuring out how to initiate an attack against an aggressive opponent. Are there any generic strategy changes that would help me, being an old player of the Soul Calibur franchise, adapt to this new system? Are there any new tricks that were added to the game to compensate for the decreased utility of Guard Impacts?
Edit: After playing a bit more, I have noticed I seem to be blocking too much. My health bar is often flickering yellow or red, and it's because I don't know exactly how to deal with an aggressive offense without Guard Impacts.
Edit 2: All the answers so far are focusing on how to use the new Guard Impact. While this is good information, it's not what I'm primarily asking for in the question. I want to know what my other options are that don't require any soul meter to employ, with a specific emphasis on strategy.