Oh yea, I've dealt with slobber. Ick! The little ones will have A LOT less slobber, trust me, haha!
I just now decided to start working on "drop it" with him. He doesn't have it down, but he seems to get the gist. We're also working on "bed time". He picked that up really quick! I'll probably focus on those two tricks (plus sit, stay, come, and down which he already knows) for the next week before moving on. I'll definitely teach him "leave it"/"take it" after that, using your method! It sounds pretty easy, hopefully he'll pick up on it.
I think I started training when Louie was 15 weeks old or so. Even the pups can be very smart and willing to do tricks! It's adorable!