One thing to remember about sheets it to dry them on a medium heat - with nothing else in the dryer- WITHOUT the use of a dryer sheet.
The more you use dryer sheets the less cotton sheets can breathe - and dryer sheets can actually cause cotton - even very high quality cotton - to pill and fuzz.
As I said above - it's important not to dry sheets with towels, with jeans, sock or with anything that has a very high level of lint in the filter after the cycle finishes.
ALSO if you have a traditional drum style top load washer - be sure to wash sheets on a gentle cycle.
This is a beside the point comment - but front load washers and dryers are SO worth the investment in how gentle they are on your laundry. From jeans - to t shirts - to sheets, towels etc. Front loaders are so gentle on your laundry - and the sanitizing cycle for sheets and towels in a major piece of mind. Not to mention the steam cycle for quickly taking wrinkles out of clothes, freshening up dry clean only items, or preventing a stain from setting it before it goes in with the rest of the laundry.
We love our front loaders! Now if they would only put them in DVC Villas!