From what I understand, the most effective way to get aid in at this point would be land-based aid through the Rafah entrance. Unfortunately, Israel has apparently been slow walking inspections. Some shipments have gotten aid in, though that is likely to lessen after the World Central Kitchen attack. It isn't the enormous volume that is capable through a larger land crossing, though.

Edit: Also, sending aid through Israeli ports is a bad idea. Right wingers in Israel have been blocking aid trucks trying to get in. Whatever route is chosen, it needs to not be beholden to extremists.