Well you can use the coffee grounds to keep the slugs away from your plants for a start off! Grit will also deter them and if your plants are in pots you can put a band of copper tape around the pot to deter them.

Zaap them with a mixture of household ammonia and water from a spray bottle. The best slug / snail killer around.
Hunt them down in wet weather.

Put down short lengths of board, or rolled up newspapers in the evening. The snails and slugs hide under them early the next morning, and you can get up at a more civilized hour, and scoop them up and bin them--or throw them out in the open for the birds!

You can use coffee grounds, but also garlic powder (equine) scattered in a wide circle around the base of each plant or row. There is also a product out used for red mite in chickens, it is called diatomaceous earth, I mix this with garlic powder and put round my crops. I have lettuces and brassicas growing away really well, un touched by slimeys.