Millie learns things very quickly. It takes maybe a few minutes for a simple trick. For things that are more accurately a series of behaviors or things that physically don't come very naturally to her it takes a bit longer.
Lucy takes much longer than that to learn something. I couldn't put a time frame on it, because she just varies so much. One reason it takes longer is that she gets distracted and bored so easily I have to keep sessions very short and sweet. It also takes more to motivate her. She learns but it takes a lot of focus and patience on my part. With each new thing I teach her she's getting better, though. As soon as she figures it out she's great at it.