First of all, I create a layer using the Add Delimited Text Layer plugin. The layer contains longitudinal and latitudinal data and a number that is assigned to each data point. When using a graduated color to style my data points, I define classes based on a specific range. I'd like to use the same classes for all of my layers. Therefore, I want to save my style using the 'Save style ...' button, in order to be able to load it into the other layers. However, when saving the .qml file, no file is created in the specified folder (e.g. desktop).
Another strategy may be to set the current style as default by using 'Save As Default'. When clicking 'Restore Default Style' in the other layers, a prompt shows up that says 'style not found in database'.
Thanks for helping me out!