Help me! Photogrammetry sucks!

I very want to learn to photogrammetry, I want to make models from great things around me including myself. But whenever I do it’s just…not good. Not good at all. A lot of parts of the model are have no textures or have a wrong shape or miss something. I have a good camera and my pc is also very powerful. What am I doing wrong? Please help

What program are you using?

The results depend a lot on the subject. There’s some objects that won’t work well for photogrammetry unless they are painted matte and given some texture.