How to discipline your teenager

Anyone who has a teenager knows how difficult they can be. They think they know it all and think they are adults but they are not. I have a 16 year old who suddenly thinks he's a man. Up until recently he has always done as he's told. I've always been strict but fair. But suddenly he has started to disobey me. This I wasn't going to put up with. The trouble I have is that at his age I was living in a bedsit with no parents telling me what to do. I could go out come back late stay out and just do what I wanted. So trying to explain to my lad that he is a child and still needs to do what I say as i am legally responsible for him till he is 18 has been tricky.  So what did I do? Well after trying to just explain to him a dozen times each time falling on deaf ears I decided I had to be tougher.  I have always believed in the old saying "you have to be cruel to be kind" so I thought how can I scare him to death so it shocks him enough to realise that if he lives with me I'm still the boss and what I say goes.  So i gave him an ultimation. I told him if he wants to live with me he follows the rules or he can go and live with his father.  At first he didn't believe me and was all cocky saying he would think about it.  Now I know this is the last thing he would want as he isn't that close to him and has said he would hate to live with him and his family. So I knew he was just bluffing. Now I had to really prove I meant it which to be honest I think I did at this point.  I've brought him up on my own without any help and it's not been easy. Part of me would love his father to take some responsibility and let me have a quiet life. So I started to plan for a life without him.  I do have plans that once I am free of kids I will sell up and buy a shop and possibly move back down south. After a few days he came back saying he wants to stay home and will do what I say. I thought this could be short lived so decided to keep up the charade. I told him I would prefer him moving out and explained how good it could be.  I tried to make living with his dad sound fun, saying how he could spend more time with that side of his family and could spend more time with his little brother and he could come see me at the weekends.  I explained how I have moved my plans forward and was looking forward to moving. Well I think this just shocked him, he hated the thoughts I was putting in his head and freaked out a bit but I was consistent and made him believe what I was saying until he broke. So it worked. I guess it was a bit of emotional blackmail really but nothing I said before would get through to him.  He is now back to his old self and a joy to be around doing as he's told. He just needed scaring. So if you have a teenager and you want them to reign them in a bit think of the one thing that they would hate the most and use it.