I am very new to modeling, and I have been modeling most of the time with subdivison surfaces, which have been working very well. But then when I tried to model a low-poly model, it tended to look very unclean and had a lot of artifacts.

I saw a video where someone was modeling something similar, and his model looks very clean compared to mine, and I am not sure why.
Are there things to look out for when doing low-poly quad modeling?
