Play up the Veil/Masquerade/etc.
Whatever your supernatural group is doing, the World of Darkness requires them to keep up rules that ban the characters from showing the world who they really are. Those rules are often enforced by more powerful or older ones from the same splat - and indirectly by other splats too!
If a Vampire acts incautiously, it's a gamble: Maybe a Garou Pack comes along and hosts a Claws-For-You, or the Order of Hermes sends an exorcist that makes lawn chairs. But the real problem is the Society of Leopold, totally normal humans armed with torches, pitchforks. They are just in the know and that makes them dangerous. They are the reason that the whole Masquerade is in place. The normal humans that just know too much. They are the Van Helsings, the Vordenburgs and Van Rictens.
Tap into the Theme
The different splats interact with humans very differently and act with them in different manners.
Changeling
To Changelings, humanity as a whole is not only giving them life, but their lack of creativity and rising Banality give them pain without the need for any supernatural foes. Just surviving in the world, facing tasks like taxes and being bombarded by advertisements is a struggle on its own.
Interactions with normal mortals outside of your circle happen all the time, and in a good part, trying to make their world a tiny bit more palatable and magical is goal of the game. At least one of them.
Mage
Sleepers are everywhere! Your goal is common ascension, your Ascension War with the Technocracy needs to be made in such a way to prevent their involvement. You need to shape your message to them in such a way that it does get accepted, that they accept your paradigm.
Vampire
Humans are Prey and Predator at the same time. Whenever a Vampire needs to feed, they have to interact with them. Just to keep their hiding place, they need to set up elaborate schemes to direct their Ghouls or servants to stay safe. Besides that, the goals of the Vampire don't neatly align with the goals of the mortal communities often, and they have to figure out ways to in influence them in such ways that they do. Be it bribing the right people or breaking bones...
You might be a monster among them, but you have to thread carefully to not pop up on the radar of a bigger monster!
Werewolf
Your enemy might be the Wyrm, but the Wyrm isn't just Fomori and BSDs and elder Vampires... it's Pentex. Pentex is a corrupt thing with subsidiaries and maybe one in a thousand is a Fomori in a First Team, but the other 999 are mortals. Mortals armed with the power of cash, disregard for nature, and enough wyrmy material to turn an area into a toxic wasteland. They don't need special powers, they are cogs in the machinery that destroys the earth. They don't even fight against you. But they are there!
And mingled in between them are the innocents. You shall not butcher them with the others, or so the tenets go. You shall not be noticed by them. They limit how you can act. They are who you actually want to help at times! They might be living off the dregs or be high in society, but they are one part of what you fight for: They are a part of the cycle. Not all of them are implicated and need to be culled.
Realise that mortals are the others to the Supernaturals.
Whatever splat you have, your players will intensely act with their own community. Be it the Freehold of the Changeling, the Court of Vampire or the Caern of the Garou: those are part of your type and the mortals are the contrast to them. To the Mortals, you are the Other, you are the monster. But to you, the mortals are the Other, you are just a normal member of your group. Once you might have been one of them, but now you are not. Contrast the societal differences, allow the players to realize that Humanity is not accepting them as who they are. They might be weak, but mortals are many.