I wouldn't say it's encouraged to give every control a custom look. It can be done, and far more easily and useful than in Windows forms, but that doesn't mean

I wouldn't say it's encouraged to give every control a custom look. It can be done, and far more easily and useful than in Windows forms, but that doesn't mean you have to use it in every application. Horrible owner-drawn controls have been a thing before WPF and just because WPF has better separation between appearance and behaviour doesn't cause inconsistent looking UIs without the developer doing weird things. The tooling you look for is probably Blend.