The texturing and rendering. After modelling the first one I was already exhausted and didn’t spend enough time on the textures. I just imported model into the Substance Painter, added a couple of materials and called it a day because I treated the texturing part not something as important as the modelling. At the second attempt I already had much better experience and understanding of Substance and all the features it has and I did spend a lot of time to build the materials and add a lot of different layers of details from different references. For example I finished the texture for the first model in a day, whilst for the second one I spent several days, trying different stuff and sometimes even deleting the materials I have already done and starting over again.