Hiking boots or snow boots in winter?
For most winter trips, waterproof hiking boots with wool socks and a pair of microspikes beat snow boots: they're steadier on rough paths, fit under crampons on a glacier tour and dry out overnight.
Snow boots earn their place if you'll stand outside for hours in deep cold — aurora nights in the north, where Mývatn's January nights average -7 °C (19 °F).
Can you wear trainers?
In Reykjavík on a dry summer day, yes. On trails, beaches, glaciers or anything wet, no: mesh soaks through in minutes, and smooth soles slide on wet rock and moss.
Before you go
Walk in new boots for a week or two before the trip, and pack wool socks — several pairs, because they dry slowly. Gaiters help on muddy summer trails and in snow.