Hello, I viewed almost every tutorial on interned how to do this but none of them worked, this one did something but it is not complete. With your tutorial I did not get my model to show but my texture {red square}. Can you please help me ? I downloaded your template and all I did is that I put my custom texture to texture folder and my model to model folder.

Thanks! I finaly got it!
The only thing is that in 1.15 it have to be: "layer0": "item/carrot_on_a_stick" and not "layer0": "item*s*/carrot_on_a_stick". But at the top it says for version 1.14 so its nevertheless a good Tutorial!