Work closely with UI designers at the company. Make sure their design process (sticker sheets or whatever) uses the components you're building and vice versa.
If developers have to twist and contort your components match mocks, then they'll start thinking "you know, this would be a whole lot easier if I just did it myself...". But if the developers get a mock that's obviously just YourDialog containing a YourRadioButtonGroup, YourValidatingInputField, and YourSubmitCancelButtonSet, then they'll just use them.
If developers have to twist and contort your components match mocks, then they'll start thinking "you know, this would be a whole lot easier if I just did it myself...". But if the developers get a mock that's obviously just YourDialog containing a YourRadioButtonGroup, YourValidatingInputField, and YourSubmitCancelButtonSet, then they'll just use them.