Pinkspoons, thanks for your help. I'm curious about your experience and expertise?
I've been a vintage retailer for well over a decade - mostly Scandinavian and Italian glass and lighting.
I'd also support what Sue says - try to handle as much glass as possible and you'll build a 'feel' for what is/isn't right (although even after years at it, it's still very possible to make some forehead-slapping mistakes). As Sue also says, regular trips to homeware shops (TK Maxx, Ikea, etc...) are helpful, too - Chinese-made glass from ten years or so ago used to be obviously Chinese (garish colours, wonky or ugly shapes, poorly-made, poorly-finished, low quality glass), but many of their glassworks have really upped their game and can be near-indistinguishable in terms of technique and finish from half-decent Murano or Scandinavian glass.