The thing I’ve found about baking is that it’s not like cooking. You can’t go off-piste with baking unless you really know what you’re doing, you have to treat it almost like a chemistry experiment and read the whole thing through first, get all your ingredients together, make sure you have enough of everything before you start. You also need to have the right equipment – cookies are a bit more forgiving than cakes because they don’t need to be baked in a tin, but you still need to use standard measuring spoons and cups and measure exactly – no heaping teaspoons, no half-filled cups. If the recipe specifies just “flour”, then I would use all-purpose. For most simple recipes there’s no reason not to use all purpose flour. Only use a specialty flour if it’s specified in the recipe, eg self raising, which has raising agents incorporated, or “strong” bread flour which has extra protein to make stretchy bread dough. Don’t soften butter in the microwave. What you want is soft, but not melted butter. I leave butter out on the counter overnight to soften to room temperature rather than microwaving. Make sure you follow the recipes to the absolute letter. But only if it is in a cookbook I know and trust. Online, anything goes, there are so many horribly-written recipes on the internet. I’d invest in an actual (vetted/tested) cookbook with basic cookie recipes like Betty Crocker or Pillsbury and go from there. Top of the list is Smitten Kitchen – I have never had a baking failure with any of her recipes. I just made her brownie roll-out cookies today with my kids and they were super easy – if you have some holiday themed cookie cutters they would be lovely with a bit of powdered sugar on them. If you’re the sort who can’t ever get the ingredients assembled ahead of time, pick some recipes that use melted butter.