What should I do before getting fillers?

When I look at my face, I sometimes feel self-conscious because it seems to have lost some volume compared to before, or certain areas look flat. Even when I try to cover it up with makeup, there are parts that don't look as natural as I'd hoped. That is why I've recently become interested in filler treatments and am researching various options. I've heard that the expected changes vary depending on the area treated, and that the consultation can differ based on an individual's face shape and skin condition. I think it's important to consider overall balance rather than just blindly adding volume. In particular, since different types of fillers have different characteristics, I'm curious about which specific product is used and how long the effects last. Before making a decision, I plan to thoroughly check for potential side effects and precautions. For those of you who have received filler consultations, what did you prioritize the most? As someone looking into this for the first time during this transitional season, please share any helpful tips you have.