/cgl/ - Cosplay & EGL

so i am planning on cosplay akko from little witch academia!! i have a few questions on what i should do about certain parts of the outfit. first off what fabric should i make the hat out of i never made a hat before and dont know where to start.Lastly what should i use (or do i make) the little brown closures on the robes? i have no idea what they are called but can i find some big enough. also i do have other reference images if you would like to see them