Some great details and examples from Luke W. of optimizing web forms for mobile entry. Main focus of this article is that standard dropdowns should be the UI of last resort. Going with a mobile-optimized option like a toggle, steppers, or custom solution can simplify mobile forms and improve conversation rates.
Awesome mobile UX idea for floating form labels
Awesome mobile UX idea for floating form labels from Dribbble. Example code is also up on Github.