Ideally, we should attract three kind of beneficial insects into the garden - parasites, predators and pollinators. When I say parasites, I mean parasites on pests not the plants!
Insects love scented flowers. Pollinated insects such as bumblebees and bees will certainly come to Nepeta, Salvia, Agastache, Asters, Echinacea, Monarda, Lavandula, Rosmarinus... Having pollinating insects in the garden is very important especially if you grow fruit e.g. apples, pears and red currants.
Plant the plants of the Apiaceae family. They are excellent insect plants as well as Compositae and Lamiaceae.
Graphosoma lineatum loves dill