I think a lot of the problem with Xander is that he was set up from the beginning to be sort of the author/audience proxy character. We're supposed to identify with him as the "regular Joe" character in the midst of all the supernatural stuff, and in a lot of ways, he seems like a teenage version of Joss, as well.
That conveys a sort of authority within the narrative (whether intentionally or not) that justifies Xander's viewpoint to a certain extent. It's great to portray a character as flawed, but when it's a character we're supposed to identify with, and he's repeatedly not being called out for his sexism and slut-shaming, what do we take away from that? That it's not really a serious flaw, that it's acceptable behavior. Sure, Buffy and Willow occasionally call him on stuff, but SO MUCH of what he says and does goes by without comment, often because it's a joke. (Since Gabs just did BBB in the feminist filter, Xander's joke about "hahaha, Buffy, I almost took advantage of you while you were under a spell" comes to mind.)
In terms of advice... I guess all I can say is be aware of the way that privilege can affect your writing? I think a lot of Xander's sexism is Joss' privilege showing through, that he thinks repeatedly joking about this stuff is okay because he's never been on the receiving end of it. Likewise, if you've never had reason to identify with someone being slut-shamed, you're maybe not immediately going to see the scene from that perspective. But if you include that POV, even if it's just a reaction shot of a character being hurt by a joke, then at least you're exposing people to the other side and not tacitly condoning the slut-shaming.
no subject
That conveys a sort of authority within the narrative (whether intentionally or not) that justifies Xander's viewpoint to a certain extent. It's great to portray a character as flawed, but when it's a character we're supposed to identify with, and he's repeatedly not being called out for his sexism and slut-shaming, what do we take away from that? That it's not really a serious flaw, that it's acceptable behavior. Sure, Buffy and Willow occasionally call him on stuff, but SO MUCH of what he says and does goes by without comment, often because it's a joke. (Since Gabs just did BBB in the feminist filter, Xander's joke about "hahaha, Buffy, I almost took advantage of you while you were under a spell" comes to mind.)
In terms of advice... I guess all I can say is be aware of the way that privilege can affect your writing? I think a lot of Xander's sexism is Joss' privilege showing through, that he thinks repeatedly joking about this stuff is okay because he's never been on the receiving end of it. Likewise, if you've never had reason to identify with someone being slut-shamed, you're maybe not immediately going to see the scene from that perspective. But if you include that POV, even if it's just a reaction shot of a character being hurt by a joke, then at least you're exposing people to the other side and not tacitly condoning the slut-shaming.