Whats the most effective method for selecting paintbrushes that can handle the intricate details and complex curves of a bike frame, and how do you balance the need for precision with the requirement for a smooth, even finish? Are natural or synthetic bristles better suited for this task, and what role does brush size and shape play in achieving a professional-looking result? Can anyone recommend a specific brush or brand that has proven reliable for bike frame painting, and are there any particular brush characteristics that should be avoided at all costs? How do you determine the optimal brush for a given paint type and surface preparation, and whats the best way to ensure that your brushes remain in good condition throughout the painting process?