Your portfolio should depend entirely on what you want to do with your 3D or other products. Do you want to find a job at a 3D company, sell models or simply create great artwork for personal use? You should try to avoid making a portfolio that tries do everything at once because it usually fails.
1.If you want to sell 3D it is better to find clients first and then create a portfolio based on what your clients like.
2. If you want to find a job as 3D modeler at a company create a portfolio based on the models they produce and must be of the same format type and quality as the company you want to apply to.
3. If you just want to make beautiful art it doesn't matter... you can create a porfolio any way you want because it isn't for business otherwise a porfolio needs to be catered very precisely to who is going to look at it.
