I have a 7 month old black lab puppy. I have been working with her a good bit and she retrieves, breaks on command, and is getting the hang of things. To this point i have only used different bumpers etc. to train her with. I am wanting to make the switch to more realistic objects. How exactly should i do so? I started by attaching wings to a bumper, what i thought would be a subtle change but it seemed to some what make her nervous. Any advise would be great.