for about 20 years i've line dried our laundry, exclusively, and in several climates/water types. i'd add to all the good stuff above that hanging right is key.
shaking, snapping and generally jostling the fibers out of their wrung-out position is essential before hanging. position items on the line so there are no new wrinkles being introduced, by working with the lengthwise grain of the fabric.
smooth and pull at seams and any wrinkly spots with your hands as you work--'finger press'. tug collar bands out straight, to counter seam puckers. hold each end of any long seam (slacks, skirts, sleeves) and pull, finger pressing as you go.
after clothes have hung for a while and partially dried, take down and shake each piece lightly, then return it to finish drying upside down. now you can pin slacks up by the cuffs, folded with side seams out, finger pressing front pleats, and pulling long seams again.
all this sounds like more trouble than ironing, perhaps, but it actually goes very quickly and requires no equipment. and hopefully you'll be outdoors, enjoying your collaboration with the air!