Bump maps. Or actually a combination. Furrowed brows are very difficult to pull off with morphs unless the topology is specifically designed with the edgeflow directed for it. I've tried it with subdivision morphs with not so good results. The creasing is difficult to pull off convincingly, at least at reasonable subdivision levels. I wasn't using a figure with topology designed for that though, LF. You'd have better luck with V4 for that. I'd have to look at Antonia. I'd say do what you can with the gross anatomy with morphs and top it off with bump or normal for the tight creasing.