bees and butterflies

If you have room, plant a Buddlaiea bush. Butterflies love it.
Bees and butterflies will gather on any of the Verbena family especially Verbena bonariensis.
Double flowers are not attractive to either because they find it difficult to get through all the petals to the nectary of the flower. The big single sunflowers are fun. I've counted over a dozen honey bees on one flower. You could try Hardy Geraniums, many of which will flower into the autumn and have single flowers. I'll let someone else carry on otherwise this could turn into a thesis! Hope it helps.

One more obvious one . In the late summer and autumn the flower heads of Sedum are often covered in butterflies.

Bees like lavender very much, though I've never noticed butterflies bothering with it. Cabbage whites seem to like Valerian, otherwise my list is much the same as BBbee above.

Cirsium rivulare Atropurpureum seems to be the number one favourite bee plant in my garden. Also I planted a small patch of phacelia (annual) which is covered in them. Any umbellifer type flowers are very attractive eg achillea and fennel (which is very attractive to other beneficial insects too). Echinacea and veronicastrum are also favourites. Butterflies don't bother with Sedum 'Autumn Joy' (Herbstfreude).

Apart from the list above, I have two shrubs which are in full bloom now and buzz when I go past them - just bee-magnets!!

One is a Pyracantha, and the other is a Photinia ''Redstart'.

Butterflies DO bother with Sedum Autumn Joy here in London - when they bloom, they're always covered in Red Admirals. Very popular with this particular butterfly.

Yes, I agree with Bamboo. They flock to the Sedums.