Out of the many fire starters, petroleum jelly balls are one of the favorites. They are small, lightweight, and burn for a long time. They are also waterproof!
The first ingredient is a material that is fluffy and fibrous like a cotton ball, dryer lint, cattail down, dried grasses, etc. This, combined with run-of-the-mill Petroleum Jelly (or petroleum based lip balm you may have in your pocket), makes for an incredible fire starter combination.
When mixed with fibrous material such as a cotton ball, petroleum jelly acts as a feul extender. It allows the flame to burn longer than normal. The fibrous material catches the flame and the petroleum jelly acts of a fuel source and allows the flame to burn longer and slower.