I grow basil because to buy it at the store is highway robbery and it never lasts. But even more than that I grow basil for pesto! I love pesto. I especially love fresh pesto. Store bought pesto is often good but too oily for my taste. Fresh is better and I can then control the flavor and amounts of oil. After my basil browning catastrophe a little bit back I only cut what I needed. Even with proper cutting some of my basil turned brown just from the trimming. Grrr. I am however comforted that some long time gardeners/farmers also have trouble with basil and it's temperamental tendencies. Read about it. This time however I rinsed my basil just before using it in room temperature water a slight bit on the warm side and had great success.
I have followed recipes in the past but pesto is easy once you know what goes in it. For the first couple of times it's good to read a few recipes and try them out to see what you like. You can also make "pesto"by trading out basil and/or pine nuts and adding in other items, lots of fancy restaurants do this. But for a simple classic pesto I use:
Lots of basil, enough to fill the food processor
A handful of parmesan
A handful of pine nuts
1-2 garlic cloves depending on size
Put everything but the oil into the food processor. Turn it on and then stream in a little bit of oil. I will even add in a little water (Gasp!) when it still needs to be thinned a bit more but I don't want to add in anymore fat. I learned this trick from Cooking Light you just have to be careful not to more than 1-2TBS because it can quickly become too thin. But don't leave the oil out, it helps give it the smooth consistency and rich flavor. Once everything is blended I taste and decide if I need to add any more cheese, nuts or oil. Its easy to add more but once you put too much of any ingredient in you are stuck.