I wish Spotify had some way for users to go into "sneaky" mode, listening to things for a few days that won't affect their future recommendations.
This kind of already happens if you listen to random things in short bursts (eg your recommendations won't change if your niece comes over and wants to listen to Justin Bieber for a couple of hours), but it would be nice to have an explicit way of turning off tracking in a similar way that you can turn off public activity.