The goal is to use a flame that will impart as few impurities into the cigar as possible. The historical method was to use a splint of cedar, known as a "spill", to light the cigar. More practical and handy are wooden matches or mechanical lighters that use butane, both of which burn clean. Paper matches are undesirable because they have two elements that can taint the taste of the cigar. First, many paper matches are dyed with a pigment. Second, they are often treated with an accelerant chemical, which you can see as it boils off the first 1/4" of the match right after it is struck. By the time this chemical has boiled off, the match is too short to light the cigar. When using wooden matches, I recommend that you use two matches at once, spread approximately 1/4" apart. This will create a flame broad enough to light the whole end in one attempt. Rarely can you get the entire cigar lit with just one match, and if you need to start a second match you have already started the cigar off on an uneven burn. Other than a thin cedar spill, these are the only two sources for flame that I would advise. Never use a candle, or a lighter that used any fuel other than butane. And certainly never use a gas stove or stick your head into a campfire, as you risk lighting you hair up when you lean over it.