Practice, practice, practice.
A little warning. Not sure what you are towing with, but short wheel base trailers (hitch to axle length) are harder to back up than the monster long trailers. I can back my 42 5er into anywhere, but I gave up trying to back in a jet ski trailer with my truck. The short trailers react to steering input much faster. A little steering wheel will make a huge movement in trailer.
Nothing to scare you, just something to be aware of. Hints that work for me is to slow down everything. Backing isn't a race. The slower you go, the more time to assess where the trailer is going and think through how you need to react before it is too far gone and you have to pull up and straighten out to try again.
Besides, if you go slow, it provides more entertainment for those of us watching.
j