The tab from the Blue Book for "And I Love Her," generated some questions at our last meet. Does this video help you? Let me know.
The main thing I think is technique. As I state in the video, the first time I played an ukulele I attempted to play it like a little guitar with guitar-like technique. It was taking the James Hill teacher training course that set me straight. James Hill has an impressive list of consultants on one of the opening pages of his book "Ukulele In The Classroom," he's really done his homework. What he came up with is that the best starting technique for ukulele is to hold it up pretty high without resting it on your leg and holding it with your hand directly below the neck. Then, the thumb is used for single note picking and for down-strums. I would think that most ukulele experts would agree. I think this works perfectly for the riff at the end of "And I Love Her."
Link to James Hill's main page:
Link to James Hill's teacher training course I attended: