If you do as the previous two commenters mentioned and change your LJ settings to friends-lock, your posts here will respect the settings you set while posting while LJ will be friends-lock. However, if you make any edits to a post on DW that is not locked, your LJ settings will change accordingly. When I was cross-posting, how I avoided that was by forcing myself to check the cross-post box every time I wanted to cross-post. Then, it didn't happen accidentally when I went back to edit something here for a spelling error.