I think that you've gotten all the best advice .....
Backing just takes a bit of practice. The back of the trailer goes
the way the bottom of the steering wheel goes, if that helps.
It is easier to back from the left (where you can see the side of
the trailer from the driver's window and/or mirror) than it is to
back in from the right.
For short trailers, go slow make small steering wheel movements
to get started ..... and start reversing your turn early in order to
prevent the angle from getting too sharp.
If the angle does start to get too sharp, stop and pull forward until
things straighten out a bit. Then ease it backward again with smaller
Definitely get a wheel that actually pins onto the nose jack. One of
the beauties of smaller/lighter FGRVs is that it is usually easy (if the
site is at all level) to disconnect from the tow vehicle and simply push
the little trailer into whatever position you want.
And ..... practice in a great big empty parking lot with striped parking spaces.
You will get the hang of it in no time ......