A sucessful way to combine perennials and bulbs is not to plan a "bulb bed" but to plant bulbs around perennials like peonies, day lilies, hostas, many geraniums, that bush out and cover the dying bulb foliage. Achillea will be no problem with bulbs, but it won't hide the foliage either. Crocuses bloom so early and the foliage disappears so fast that they can be planted almost anywhere.

You might try perennial geraniums. Annuals that can be sown directly into the bed, like cosmos, four o'clocks and California poppies, should camouflage well without disturbing the bulbs.

Most yarrow like it kind of dry, so they should do alright in a bed with lots of bulbs. Generally you shouldn't plant perennials that need lots of summer watering in a bed with lots of dormant bulbs.

Another readily available easy plant that likes it somewhat on the dry side is gaillardia with cheerful daisy-like blooms. They bloom all summer and have nice seedheads. These have recently come out in some new color varieties.

One note: Yarrows & gaillardias don't need real fertile soil and tend to flop more when in rich damp soil.