For easier murdering, I place pieces of plywood around the garden, starting in winter. On a regular basis, I turn these over and kill any slugs hiding beneath, using any sharp instrument or rock to cut them in half,or just squash them if tiny. In early spring, they are tiny, but now, there are some bigger ones. The idea is to cut down the population of slugs. I also have a large rosemary plant that needs constant trimming, so I place sprigs of rosemary around the vulnerable plants, to repel slugs. I also use slug bait - again to cut down the population. I just tried copper collars on cabbages, but feel the money could have been better spent. It seemed to work, partially, but not entirely. Another hiding place for slugs is among rocks that are piled up. Note: I have had no luck with beer traps. Oh, and I have gone out in twilight and hunted in the grass, especially in summer when they are large enough to see easily. Good luck!