Teysa is tailor-made for all those Afterlife cards that you can now play in token-based decks. If any of your cards have Afterlife 2, then Teysa will create four tokens instead of two and will give them Vigilance and Lifelink, which can be quite overwhelming.
Teysa and Judith will work amazingly together in Mardu token lists, which can go wide very quickly. This kind of board will look so threatening that you may see opponents quit just out of sheer desperation.
But that is not the only possible combo you can achieve with Teysa Karlov, so just keep experimenting until you find the right balance.