So many factors and one big one is the manufacturer and the car. Some companies subsidize their leases on certain models for many different reasons. I have a lot of experience in this area and happy to help. I'm a guy who leases all cars but my last one I bought because the lease on this model just didn't make sense. The make and model really matter on what incentives the dealer will provide.
As for the broader question: when I leased I always had them throw in all service, 15K miles and able to flip out of them relatively easy. Again, this will depend on the make and model and what your goal is in terms of the purchase. For me, I didn't like driving cars longer than 30 months-3 years because that's when you have to start replacing tires and brakes etc...My goal was to have a car payment like a utility bill. It came out of my direct deposit each month and I would never own any additional money for service or tires/brakes etc....
My recommendation: find a 36 month lease, get your service covered and given how much you drive 12K per year will be more than fine. It would be helpful to give an idea of what kind of car. Your value on the lease will depend on how the car depreciates and what incentives the company offers.
Here is an example: Mercedes gives crazy incentives on their C and E class models to lease. They subsidize their C 300 and 350. You can get these shocking cheap because they know once you lease one they have you for a long time. They'll be selling you a new car every 3 years. They have a new 450, you can't lease it because they offer no incentives because it's new and hot. Same thing on an E class. It's one example but the type of car and model greatly determines whether leasing makes any sense.
