Running

With it getting colder and colder outside i find myself wanting to upgrade my running wardrobe. Maybe you guys find yourself in a similar situation, or have already found your endgame and can give some recommendations.

Right now for example i am looking to upgrade some of my cheap decathlon longsleeved tops, that i am not particularly happy with, and maybe add a jacket/vest.

What are you wearing when it is X°C outside? When do you start using multiple layers and what's your strategy?

What are your favorite pieces of running gear for when it gets cold outside? Feel free to name specific models.

Or maybe you aren't as hung up about a specific brand, but have certain features/materials/technologies that you really like/dislike in your winter gear.