Well if you want to make sure that you're always logging all channels, all chat windows and all query windows you could use this...

Code:
on *:OPEN:=: {
  .log on $nick
}
on *:OPEN:?:*: {
  .log on $nick
}
on *:JOIN:#: {
  if ($nick == $me) .log on #
}


~ Edit ~

Paste that code into your script editor (alt+r) under the Remote tab.