I get so frustrated every single time I bake cookies because they always turn out harder than a rock. I have my oven light on and check on them all of the time. I also take them out when they are pretty soft, but they continue to cook when out and then as soon as they cool off.. *poof* hard cookies.

Any suggestions?

Use a wire cheese slicer dipped in flour to cut uniform-size cooies from refrigerated dough.
Shaping up: Dampen your hands. It makes it easier to shaped cookies.
Here is a timesaver that eliminates the need to chill dough: Place dough between two pieces of waxed paper cut to cookie sheet sixe.
Roll out 1/8" thickness. Lift off top sheet, cut out cookies as close together as possible. Then put dough in the freezer 5-10 minutes.
When it's firm, cutouts can be easily lifted off with a spatula, & they won't lose their shape. Reroll excess dough & repeat. Make square cookies with a pizza cutter & save time.

Less handling means they'll be less tough.

To make it softer, how about using cooking oil instead of butter. When I started using oil instead of butter, my cakes tend to become bouncier and softer. Maybe that applies to cookies too.

you can try adding a package of plain vanilla pudding to your dough. It helps them stay soft and keeps them from spreading (fluffier).

I usually take them out before they are completely done. If the recipe says bake for 8-10 min, I usually pull them out after 6 min because the sugar in the dough retains enough heat to cook them an extra 2-3 min. This usually helps keep my cookies soft.

Also, don't put them in the fridge... my daughter did that with my last batch of cookies. When I went to eat one, it felt like I chipped a tooth. I know I didn't though, but that cookie was harder than concrete.