is it me, but when I think of ska I think of palm mute downstrokes and then accented upstrokes? Or at least that's what I do the few times I play in that style. Sometimes I'll also do it all downstrokes, and for the mute I'll hit more the fatter strings, and then for the actually clean cord I'll strum more on the higher pitched strings.
I don't play the styles very often, but hopefully someone else can give you better tips. It always take a while to get a new strum pattern down, and I think for me the best way is to just play along to the song over and over. I'll make a ton of mistakes, but it's like eventually I'll stop thinking about it and my hands will start to sync up to my ears. Kind of like riding a bike, more automated trial and error rather than conscious though.
