Hmm would definately think you'd need a tree or medium shrub of some sorts, pref a nice hawthorn, pyrocantha, cotoneaster or rowan; this would give them something to fly towards and take shelter in. Plants are usually the key as they provide shelter and insect nosh in time as long as you don't use any chemicals to kill off the aphids etc. Water is also really important either in the form of a birdbath or pond, the latter would serve as an insect lure again providing extra food for the birds. It's a great joy to plant up a garden and use it to be part of the environment, good luck