Air if space, time, and weather allow, @Laura1901. I find it more economical, and not a great deal of work. I love my huge outside clothesline and pretty sheets flapping in the breeze, but I have an inside drying rack for blizzards and rainstorms. I use the gas dryer as a last resort when there are too many turnarounds and I have hit the bottom of the sheet stack.
Like some of the hosts here, I do touch up the wrinkles with an iron.
@Laura1901, I always air dry for the following reasons:
I live in a pretty rainy place so I can't always get the sheets dried fully, especially in winter. However, I always hang them up until they are almost dry, then finish them off in the tumble drier only if necessary to get that last little bit of dampness out of them. I have both an outdoor line and under shelter line in case of rain.
@Rachel0, thanks for the tip about fabric softener - I've been using it ever since an (older) guest said my sheets smelled 'interesting'. As I only use natural products, I'm assuming she meant they didn't have the perfumed (and to me, horrible and fake) smell of highly fragranced laundry products. Since then, I've been using a natural fabric softener to ensure the sheets and towels smell 'nice'. But, you may be right about absorbency - I think I'll stop using it and maybe just add a few drops of essential oils to the wash instead.