Most people use raw pine nuts, 1 small clove of garlic, a bunch of basil, extra-virgin olive oil, grated parmesan, and a little salt. That pesto can be great, but I like to make it special, so here's what I do:
1. Toast the nuts
I toast the nuts gently at 325 degrees for 4 or 5 minutes until golden brown. I am famous for burning nuts -- use a timer! -- so check them at the half-way point and shake the nuts around in the pan. Then I let them cool to room temperature.
2. Grind the cheese
In the meantime, as the nuts cool, I skip the laborious method of hand grating the cheese. Instead, I cut up the cheese into large chunks:
...put them into the food processor, and -- using the metal knife blade -- grind the cheese into tiny pieces:
Now, this might seem odd, but I make the choice to do it that way because I like the way pesto tastes in my mouth, with the cheese pieces being more present on my tongue. Take the cheese out of the work bowl and set aside.
3. Use more garlic
Entirely up to you. I love garlic.
4. Pause to sniff
Put the cooled nuts, garlic, about a quarter teaspoon of salt into the work bowl and let it run. Then open the lid, lean your face into the bowl, close your eyes, and breathe in. Mmmmmmmmm. After that moment of joy, use the spatula to scrape the mixture off the sides and bottom of bowl to reincorporate the mixture.
5. Wash leaves THOROUGHLY
Don't be lazy. Dirt has an easy way of destroying your experience. I use a salad spinner. Let the leaves dry thoroughly, too.
Put the leaves into the work bowl and at the same time, drizzle olive oil through the feed tube. I use about two thirds regular olive oil and about one third extra-virgin olive oil. This is a personal preference. Given my approach to the pesto -- toasting the nuts, grinding the cheese -- extra-virgin olive oil has an intense flavor and yes, it is better to use in un-cooked preparations, but in this case, I want the toasted nuts and ground cheese to be the star of the show. I don't measure the amount of oil I put in because every batch is different; I let the oil run into the mixture until all the leaves are incorporated. Stop the machine, scrape the sides of the work bowl, put in a handful of the already-ground cheese and pulse until combined.
Use your own judgement seasoning your pesto. I err on the side of less salt in the beginning because cheese can be salty. If you're low on basil and you happen to have parsley, a blend can be a nice change.
If you're feeling adventurous, try hazelnut-parsley pesto using the same method. I don't know that I've put that pesto on a pizza before, but it definitely makes sense in lasagne (eggplant lasagne with hazelnut-parsley pesto -- a fan favorite) or any other pasta dish.