The gentle lead halter has been an amazing tool for us. Penny has big issues when she sees strangers, other dogs, etc. I had a trainer recommend it to me, and it has done wonders as far as keeping her under control.
Here's a link to the one we purchased:
Link
Penny can still eat, drink, bark, play, etc. with this halter on. It just gives you the control and reminds them that they are to follow your command and your lead.
We bought the Small for Penny in a gold color so it blends in with her fur. And we are planning to get one for Riley as well to aid with her training when taking walks.
Good luck!