I've been using traditional signs in my game for RP. Before Seasons, I was playing a long game with "seasons" in mind but the duration doesn't quite work out now. I played a custom "Epic" game with six day seasons but that's kind of gone out the window because "omg holidays :D " but also "omg no seasonal slider D: "
So that's all kinda gone out the window and I have so much math to do but here's what I do.
All of the sims I make or are born into my families end up with two mostly positive traits and one negative one with careful consideration for their bonus trait. If they're a young adult or older when I make them, I'll also give them one or two additional reward traits and a couple character value traits from Parenthood. Their signs mostly show up in what activities they like, what careers or clubs they'd gravitate towards, how they look, what they decorate their living spaces with, that kinda thing. After a good while, I'll age them up according to when their birthday should be.
As an example, Scorpio could be a Genius (because they get Focused easy), Self-Assured and Jealous, with the Alluring bonus trait. They could be a Detective or Scientist and like yoga, music and reading, and gravitate towards the colors red and violet. Their birthday would be in the last third of autumn. I usually base toddler traits more on what their home life is like but they could be Inquisitive, Independent or Clingy.
There's more to them than just their zodiac sign but it does mean that I use a wider variety of traits and trait combinations when I'm handing them out. It also means I kind of avoid the death waves when birthdays are spread so far out so all the elders don't die on the exact same day. x_x