I always use real butter, regardless of what the recipe calls for. I also soften the butter in the microwave but I do not melt it. I use a good quality vanilla extract and I like to double the amount of vanilla the recipe calls for. This gives them a great flavour. It is also important to mix your dry ingredients well in a separate bowl from the wet mixture and then once your wet ingredients are mixed well, then you can add your dry ingredients. It also helps to have a good quality mixer. I have a Kitchen Aid Stand Mixer and it is awesome for mixing cookie dough.
Another great tip for perfectly browned cookies is to line your cookie pan with parchment paper. Your cookies will never sick to the pan and they will cook evenly and brown nicely on the bottom. If you like a soft cookies, bake them for about 8 to 10 minutes, depending on your oven. If you like crispy cookies, bake them for 12 to 15 minutes, again depending on your oven.
I hope these tips will help you make a perfect cookie!