I'm not a military expert. I don't know. There just... HAS to be a better way.
Here's your key problem then.
There
isn't a better way.
There is
no way to have a military conflict without having civilian casualties, unless it's incredibly small and focused, like a single battle fought in an empty field. After the conflict, there'll probably be a few minor ways around the edges that failed to be implemented, but nothing systemic, nothing that would have dropped casualties by 90% or similar.
The war between Hamas and Israel is in a
city. There is no way to have such a war without civilian casualties. If
both sides were interested in avoiding civilian casualties, you might be able to cut them down to a very low level, less than a thousand perhaps, but that isn't the case.
It is Hamas's open and explicit policy to actively use the inhabitants of Gaza as human shields, both to discourage Israeli military efforts, and to use as PR material on the international stage, to try to make Israel look bad.
There is very little, almost
nothing, that can be done in such circumstances to mitigate casualties. Warning civilians to try to evacuate is the larger part, and rendering medical aid to injured civilians after an area is cleared of hostiles is most of the rest. Even that though, is spoiled to a significant degree, because Hamas is absolutely not beyond having their members pose as injured civilians, and then suicide bombing anyone who tries to help them.
With the enemy
actively trying to increase civilian casualties, almost everything you can try to do to mitigate them, will instead make it worse.
If you try to use less powerful munitions? The conflict lasts longer, and more civilians are killed over time, on top of more of your own soldiers.
If you try to be more cautious in your attacks? The conflict lasts longer, and more civilians are killed over time, on top of more of your own soldiers.
If you try to send supplies to civilians? Hamas ceases them, maybe kills any civilians who resist the seizure, and uses them to strengthen their own militants, so the conflict lasts longer, and more civilians are killed over time, on top of more of your own soldiers.
We do not leave in a neat, orderly, or pretty world. We live in a messy, ugly world, where death and suffering are easy, and stable, peaceful society with low death rates due to violence is a rare and hard thing to sustain.
Hamas has no interest in any of the things we consider hallmarks of a 'civilized' society. Genocide, jihad, and world conquest are their explicit agenda.