Soft fruit can be protected with taught mesh nets, by stretching them over a woodern frame one can lift the whole contraption off the fruit and get to it for weeding or picking- the taught net can be big enough for any insect to get through as caterpillars from butterflies are not a problem here- but i found that birds would often get caught up in loose ones (drapped over wire poles) and be found dead the next morning which is quite disappointing for some young child to find... basically the net should be able to support a domestic cat in weight and allow birds that don't see the net to bounce off without getting tangled up-
As for slugs i use organic pellets based on ferric phosphate and is promoted by the organic farmers and growers thingy as said on the label- a few years ago i poisoned my cat with ordinary slug pellets when he ate a frog in the back garden - he did survive but it did make him very ill- think what they do to wildlife and i've been told that one ordinary pellet can kill an elephant! not sure if its true but i wouldn't like to try it.
Commercial growers have been trying with off the ground techniques and grow them in an open drain pipe laid on its side- being easier to pick and apparently water too- the added bonus is that the fruit is off the ground and no need for straw of chemicals for slugs etc as they can't reach them! they also grow them in polytunnels so birds are not a problem either... but thats the way the farmers grow them anyway.