Apart from being able to teach the dog what he should know, the handler himself should:
1 Be able to interrogate the witnesses as to where they think the deer was hit.
2 Be able to confirm their opinions with a thorough investigation of the shotplace.
3 Form a plan of action to find the wounded deer.
4 Make a hairbook.
5 Whilst following the trail be able to read his dog so that the dog can be gently corrected if he makes a mistake.
6 Elementary things like knowing boundaries, the law, marking a trail and suchlike I leave to your imagination.