Don't wait until someone dies in order to say something nice about them. There are likely some people you know that are either your enemies or former friends or even people you are friends with now but don't talk to very often.
Don't wait until they die in order to say something nice about them, and then think you're honoring them and their friends and families by saying that. That's actually a huge insult both to all of them and to your own self. Being two-faced is dishonoring who you are. And lying to them or waiting until the person dies in order to say something nice is an insult because why should it have to take someone dying in order for you to say something nice to them? Why couldn't you say it while they were still alive?
I'm not saying you have to say mean things about a person after they die because obviously that's a whole different kind of not cool, in the opposite way of the point I'm trying to make here. Because in that situation they can't defend themselves.
What I mean, is take a look at the people who you know that are still alive. And find some way to show them some form of honor and respect now, today, while it can still mean something to them. Because if they aren't alive to see it, what should it matter to them how many nice words you say about them? They'll never get to rejoice in what you could've said. It's always a great feeling when an enemy becomes a friend, especially if the enemy had previously been a friend of your's.
And if you still want to dislike someone and not show them any form of honor and respect, then don't show it to them after they die. Because who they were while they were alive is no different now that they're not alive anymore. If you really respect a person, show it to them while they're still alive and if you really respect them you will respect them for who they are, and that includes both their good and their bad traits, and whether they're alive or dead.