I use beer traps, which is an excellent way of luring them in, or pick them off and put them in a large jar of water and salt, screwing the lid on. I only use slug pellets in the greenhouse on my young seedlings.

Crushed egg shells are quite good and are free! Copper iin the past has really not worked for me and its expensive.

Nematodes are excellent and I use them twice a year, good to buy from

Pest Control.