I realise that this is not directly concerned with TeX and friends but it is about improving my answers to such questions.
I try and provide an MWE in my answers and I want to show their typeset output which is a PDF file. I have seen that I should use
convert file.pdf file.jpg to produce a JPEG file for inclusion in my answer. However when provided in my answer the result looks small and blurry whereas I have seen many other answers with good looking graphics. How could I do that? (I have used GIMP to trim the JPEG files but this only removed irrelevant space and left the poor quality image as it was).