How do I approach a property owner and ask if they want to sell?

[Skyler Horton]

I found a triplex in my area that is vacant. With a little elbow grease it will make a great rental. I did a parcel search and found the owner. Now I have to contact her to ask if she's interested in selling. Should I call; send a letter, or go knock on her door? I am afraid a letter might be ignored and a phone call might not relay that I'm serious about it. Any advice would be helpful. What is everyone else doing?