Today, I discovered a way to encourage a new package/swarm to build straight comb. It seems to involve using one or more starter bars with vertically hanging wires. I've diagrammed this type of bar on my blog. It seemed like a novel approach (at least I've never read about it before), so I thought I'd share it since a lot of people appear to have difficulty getting bees off to a good start.
You can see this technique at: http://happyhourtopbar.blogspot.com/...-building.html