Yes the copper tape works very well. I have saved several plants with it, and its good for things in pots. Otherwise the only truly effective way is to go out at dusk with a torch and pick them off and put them somewhere else a long way off
I used to spend heaps of money on safe slug deterent which was supposed to keep them away from plants and it didn't work. Sprinkling ash works a bit but you end up with very dusty plants...