Only flannel sheets I've bought balled up on me and were itchy but they were cheap and poorly made.

High thread count doesn't necessarily mean quality. It just tells you how many threads are in a square inch. The higher the thread count, the stiffer the sheet because of that many threads in the square inch. If you like crisper sheets, those are the ones to look for.

What kind of thread and how it's made is what makes the sheets quality ones. Look for what kind of cotton is on the package and that will help. Egyptian Cotton is among the best. Most are a polyester/cotton mix though. Polyester adds stability as cotton has long or short fibers to make the thread. Short fibers fall apart easily so look for long staple cotton.

Bamboo sheets sound amazing. I'll have to look into them.

I don't know about the microfiber sheets. Those sound wonderful as well.

Didn't plan on giving a science lesson, but I hope it helps when you look at the package.