Empty car park, ideally lit (if at night) or in daylight, practice until you can do it with your eyes shut - I used to do this when shunting empty trailers, it's a good feeling when you get it spot on literally with your eyes shut! 
Brave post, but good on you for admitting you fail at parking but want help!
Brave post, but good on you for admitting you fail at parking but want help!
