Tin whistles don't exactly stand tall in the pantheon of high-maintenance instruments, but there are some simple things you can do to keep your whistle happy:

• If you buy a whistle and find it's not quite right, the Ceolas Tin Whistle Guide has a few suggestions on achieving perfection (see the sections "Buying, Brand Comparison" and "Tuning").
  
  
• On Lark in the Morning's Flutes and Pennywhistles page, Ian Law explains how to care for and fine tune your tin whistle. Explanations are concise but straightforward.
  
  
• Whistle maker MK Music offers tips on tuning and caring for your tin whistle. Most of the tips, though, apply only to their own, high-end whistles.
  
  
• Kim Fulton-Bennett provides guidance on the care and feeding of the copper pennywhistle. Additionally, he offers tuning suggestions.
  
  
• More tuning tips can be found at TinPenny. The author deftly describes (in a single paragraph) the process of loosening a whistle's head to change its tuning.
  
  
• Whistle maker Thin Weasel offers tips on caring for your Thin Weasel whistle, though many of the tips apply equally well to other whistles.