A diversity of all kinds of plants will create a habitat for all kinds of bugs. So don't just think flowers, but other plants as well, both annual and
perennial. The goal
should be larger than just pollinators --- shoot for a biointensive natural environment with all kinds of insects and soil biota. A garden with 100 different plants growing in profusion will be a magnet for insects.
Insects need places to lay their eggs,
shelter during difficult weather, over-winter, and protection from birds and other predators. Don't clean up every dead plant at the end of the summer growing season, but leave some of the spent plants for them to overwinter. Mulch (
wood chip mulch is garden gold) creates a habitat for ground loving beetles and anthropods. Letting common garden veggies like carrots and beets, or herbs like dill or basil go to seed provides food for a wide variety of creatures (and seed for yourself for next year's garden).
When in doubt, plant more diversity. And comfrey. They'll show up and stick around if you create a habitat that they are excited to colonize.
"The rule of no realm is mine. But all worthy things that are in peril as the world now stands, these are my care. And for my part, I shall not wholly fail in my task if anything that passes through this night can still grow fairer or bear fruit and flower again in days to come. For I too am a steward. Did you not know?" Gandolf