I've tried beer tin traps as well. They indeed attract slugs, but I'm not sure it improves the situation long term.
What worked for me is:
Get the seedlings as big and strong as possible before planting out, so the terminal bud is already high above the ground and better protected. No harm if slugs eat some lower leaf, but damage to the terminal bud can cripple the whole plant.
Water only in the morning on hot days, so the ground has enough time to dry on the surface (= less slug traffic).
Cover small plants with Agribon-like material held by a circle of stones (does not help 100% against slugs, if the ground is already infested, but reduces damage from birds, insects and weather impact.)
A Sluggo-like granulate from iron phosphate called Ferramol, sprinkled around the perimeter AND around the common slug-hideouts (i.e. wet places under plants with big leaves), also around the beds (so the slugs find and eat it before they find the seedlings). I start early in spring, before the first big slugs appear, which seems to prevent that dramatic population explosion during rainy periods in summer.
I always plant some early
in pots on a gravel bed, and protect the pots with Agribon until the plants get too big. This way a minimum harvest and some fresh seeds are almost guaranteed.
I once had a small field full of seedlings, badly damaged by slugs, birds, late frost. For long it looked like nothing will come out. Eventually most recovered and popped to an impressive size. The ones at the edge close to the grass and especially the ones next to some shrubbery had a visible disadvantage, though. The plants in the centre did best.
Since then I add sunflower seeds to the tobacco beds - when they germinate many get eaten by the slugs, which in return seem to focus less on the tobacco plants. Some sunflowers make it, they are doing well together.