I always start with nets on, get the pup used to rabbits in the net, let it hold them in the net, when happy, leave a couple of nets off, let it chase back to other holes, encourage the pup to fill its nose with scent at the hole. Leave the nets off for a couple of chases, then when the penny has dropped combine it all together. Marking, working the nets and chasing bolters. Patience.
thats what this site is all about good sound advice exactly the way it should be done {in my oppinion}