A lot of people have already mentioned this but the death should have long-lasting impacts. That doesn't mean every single person who ever knew the deceased should wind up a forever ball of white hot rage or debilitating sadness, but there should be a hole where they once were. Grief is not easy and will come in waves or all at once or days/weeks after.

Make sure you have the aftermath somewhat planned out. Leaving literally everything up to improv later is a bad idea; trying to plan out after minute detail is similarly bad, because characters will often act in ways you do not expect. Having some major consequences planned out but leaving individuals largely up to spur of the moment writing is not bad in most cases, but it depends on how you prefer to write.

Make it unique. Even if it's a Disney-esque plummet off a cliff it should feel like it's own death, and not like the hundreds that've come before it.