Snails are so common that it's unlikely that any treatment applied will minimise damage. There are some preventative measures to help control their numbers in the garden:
Attracting natural predators into the garden should always be the first course of action. This can be done by letting corners of the garden 'grow wild', plating a selection of pollinator-friendly flowers, or incorporating things such as birdbath, tables and boxes.
Choosing to plant sturdier, established plants, as opposed to seedlings, will aid recovery from any damage inflicted. Keeping seedlings covered at first can offer some protection too.
Barriers can be made around plants using lime, forest bark, crushed eggshells, wood ash, human hair and soot- but their effectiveness may be weather dependent.
Buffer crops can help save prized plants, so by planting some extra lettuce you can
Torchlight searches on a damp evening can be useful. Picking off snails and placing elsewhere, or on a bird table can help to prevent damage.
Raking soil or picking up leaves can expose slugs to wildlife like birds.
When digging in Autumn, make sure you're removing slug eggs as and when they're found. They're spherical and translucent.
Beer traps can be left near vulnerable plants to trap slugs. These should be checked and emptied daily.