its been awhile since i trained mickey (he's 13 so def been awhile!)
whenever i tried to teach him to shake i'd have him sitting (by this point he mastered the sitting) and i'd say "shake" then grab his paw then say shake again then give him a treat...
in the beginning stage, he's try to pull his paw away because he wasn't comfortable with it. but by 5th time, he realized that i'm not hurting him and there was a yummie treat in it for me to grab his paw, he was completely cool/fine with it...
just make sure when you take his paw, do it lightly and not for very long time.
say "shake" before and as grabing the paw say "shake" and then let go. this process should only take few seconds...
hope this helps!
