We talk a lot on here about fire starting methods and materials but I don't think I've ever heard the answer to this question: Are fire starting methods dependant on anything other than personal preference and the availability of materials? I'm thinking particularly about using natural materials. A magnifying glass won't work without sunlight but, for example, would there ever be a time that you'd choose one friction method over another? When would you choose a hand-drill, fire plough or a fire bow, for example, if you had the right materials on hand for either? I imagine that temperature, wind, moisture and altitude might all play a role in any given method, making some more effective in certain situations than others.