The best thing about a beauty trend is that you have a little time to observe its success or failure on others before deciding you want in. In fashion, if you take three months to decide that denim harem pants could work for you, you'll have missed the boat (incidentally, you'd also be wrong).
Beauty tends not to have fads and crazes, so much as modes – longer, gentler cycles – which means that even now it's not too late to hop on an autumn/winter look. Especially since, in the case of the full, 1960s-style lashes on the catwalk at Miu Miu and Chloé, this one is universally flattering.
If you haven't Twiggy-fied your eyelashes thus far, do it now while the light levels are still low. Va-va-voom mascara, which for period authenticity should be applied liberally to top and bottom lashes, is a look that goes off in the summer sun, not least because the smudge factor is higher in the heat. However, that's not to say that it can't look fresh; just keep everything else simple.