If you want to make a ditch jump you can buy two 6ft 4in x 4in and buy some black plastic and nail the plastic to the poles and then roll it onto one pole.
And you can put a hole through the poles so that you have a hole on each flat face then you can put a pin through them to hold it in place.
Then you can start of jumping a small ditch without digging a ditch and once your horse is happy jumping it you end the day on a good jump.
And the next time you go and make it wider and jump it and you just keep it simple on the width.
And before you know you can jump 4 to 5ft wide ditches......alan