I break down items into portions. Usually a "portion" for me is what fits in a "snack sized" ziplock bag. Some items (like quarters) take "sandwich sized" bags. I put the bagged items inside larger freezer bags (labeling if necessary). For organs, since I feed daily, I bag smaller sized portions that approximate 10% of a daily meal, and feed liver one day and "other" the next.
Having portions ready to go I can mix and match meals quickly, picking of a number of portions RMBs, fish, meat. etc to feed that day aiming for a balanced meal. Keeps it fast and easy, but does requires advance work.
I mostly (but not always) feed frozen.