Aside from the obvious (free shows at Yonge-Dundas Square Thursday to Sunday), a massive fest like NXNE offers plenty of free stuff - musical and otherwise.
The waterfront's Harbour Parklands (Queens Quay at Ferry Terminal) gets a head start on the official music program with shows on Saturday and Sunday (June 14 and 15) afternoons; Market Lane (Front and Jarvis) hosts noon-hour concerts on Tuesday (June 17) and Thursday (June 19); and Trinity Square Park (Eaton Centre Courtyard) is also doing the lunchtime thing, with the Shoe (featuring actor Jena Malone) on Monday (June 16), and folkie Briar Rabbit as well as singer/guitarist Toby Goodshank on Wednesday (June 18).
Plus, some venues have freebie food, drinks and goodies. Check event sponsors for an idea of what might be on offer. This year, look out for products from MiO, Fruttare, Kind Snacks and Tito's Vodka.
More info here.