We've made 3 loaves so far in our bread machine, using the recipes in the supplied book.
They've turned out dense and cake like, especially the third one using strong flour, but all were still edible.
Has anyone got tips on getting a result that's lighter and more like bread?
This implies the first two were not made with strong flour. You can't make acceptable bread with baking flour, it tastes like biscuits or cake and it won't rise properly.
You can't use normal granulated dried yeast in a bread machine, you need the fine "quick action" yeast. Make sure it's in date and less than a couple of months since opening.
Don't skimp on the salt. 10 ml of salt is normal for a large loaf. Don't be scared, it's not like you're going to eat the whole loaf at one sitting (and if you are, you have more problems than sodium intake).
Measure as accurately as you can. If you have digital scales, weigh the liquids instead of using a jug.
Try a "bread mix" in your machine, if that doesn't work then it's the machine that's shit, not your ingredients/technique.