It is important to continually survey any plant damage to see exactly what and where the pest damage is. Often the pest damage is not that big of a deal. I believe 10% - 15% crop damage is fine for organic gardens, and this gives the beneficial insects a chance to build up its populations. But if its significant then some sort of action is required.
If it's the leaves, look at the whole leaf… the outer, underside and edges of the leaf to see where the damage is. Often an insect will leave behind digested waste or residue, which is a clue to what type of insect it is. Snails and slugs for example in leave behind a shiny path of slime and droppings.