Sophie, as a few others suggested we just started a bath/story/bedtime routine each night. We would start around 6pm and I would offer him a feed after his bath. It only took about a week for him to get the hang of it. We started this when he was around 3 months old. He doesn't sleep through the night, but he does wake just to have a feed and then goes back to sleep. I make sure I keep the house dark, feed him, rock/cuddle him and he's fine to go back down.
My DH works nights so our evenings are really rushed and busy, but it has made a huge difference having a bit of routine in our lives.