That was fantastic, thanks!
Some of the key things were to put separate powder in for the pre-wash (mine doesn't have a separate pre-wash section as far as I can tell), and to not put so much detergent in. We have soft water, and apparently that means if you fill the thing up (or use a tablet/pod) then you might be using too much detergent which means it might not all come off in the final rinsing stage.