Limoncello is easy, don't over think it. I have a generic lemon tree in my backyard also. Zest the lemons and soak the zest (no white pith!) in the dark in a bottle of Everclear. Cheap vodka will work also. A month aging will do, but the end date is pretty wide open. I sweeten it after it's done. You can add cream to it and make the wonderful crema di limoncello also.
I've made orangecello. I've made grapefruitcello also, but I don't recommend it since there is something in the GF zest that makes my tongue go numb.
