Good colour management strategy dictates that you should always calibrate your device first before creating your ICC profile. This is colour management 101!

Calibration - the process of bringing a colour device (i.e. monitor or display, printer, and even a scanner...) into an optimal, quantifiable, repeatable state. This condition could be an industry standard, manufacturers spec or guideline or your own specification. https://www.colourgraphicservices.com/services.html