How to improve your space for nature: be philosophical
Not everything is going to thrive in your particular outdoor space. It might be too shady for herbs, or to hot and dry for whichever happens to be your favourite plant. The soil might be too acidic for some of your favourites too. I’m a great believer in giving each plant a chance. If it does well, great, keep those. If it withers and dies you know your garden isn’t suitable for that particular plant. Move on. I have tried to plant foxgloves in my garden for years (I’m stubborn that way), they’re supposed to be a weed. People warned me that once I’ve got them I’ll never be able to get rid of them. They have never taken. Hellebores on the other hand, that are supposed to be tricky, behave like weeds in my garden and have self seeded all over the place. So I accept the hellebores and have given up on the foxgloves (ok, I buy a couple for pot plants every year - the bees love them).
Most herbs produce flowers that are great for insects. They may look small and insignificant, but they pack a nectar punch. Marjoram, lavender, thyme and rosemary are all great for flying insects. Herbs are also very easy to grow, tend to be hardy, cheap and as a bonus can be added to your food too. No balcony or garden should be without a collection of herbs.
Animals that eat our fruit
Birds and mammals love the fruit we love, so if you are trying to grow strawberries, cherries, apples, and the like you are going to face fierce competition. The best way to protect edible fruit is to put them in a fruit cage. I.e. A space covered in netting too fine for animals to be able to get in. Insects will still be able to get at the fruit but birds won’t be able to. Animals can take a long time to realise there are fruiting plants about. I planted a morello cherry in my garden 17 years ago (morellos are great because they can tolerate shade and are small compact trees). For 16 years the birds hardly touched the tree, then last year a pair of blackbirds built a nest in the ivy nearby and for the first time ever I didn’t have a single cherry, they got snaffled by the blackbirds. As I planted the tree for wildlife I’m not complaining. They’re welcome to the fruit. I have a similar experience with my strawberries, the only competition I currently have for them is with the slugs.