3 options:
1) default, if the character creation tools are annoying
2) to fit the 'build' im going for, e.g. a strength user in Dark Souls, ill make them look a bit beefier than a dex one, sometimes mix it up for some variety like a big nimble guy, or a tiny person with massive strength etc.
3) if the game takes itself really seriously, or is a comedy game ill often make a ridiculous looking character for fun
dont really go for making them look like me because it just gets frustrating and it never actually ends up looking at all the same