A bowl of beer buried to the lip in the soil is an oft recommended control practice. Apparently the slugs are attracted to the fermenting yeast smell. So this tells me you could use yeast as well as beer. I've heard mixed reports from this, saying that the dog drank the beer, leaving a happy dog but frustrated slugs. You'll have to try it out yourself as I've never done this.
Barriers work well.
Wood ashes, diatomaceous earth, cedar bark, cinders and continuous copper strips can be effective barriers to slug travel. Copper barriers apparently interact with the slug to produce a mild electrical shock. Make sure there are no vegetation bridges over the barrier that the slugs can use to circumvent your copper moat. Ashes and diatomaceous earth are only effective when they are dry. I've also heard some gardeners use salt on the slugs.