Smell it before you light it. Soy wax holds scent well when cold, so you'll get a good sense of it straight out of the box. With a sample this size that's often the most accurate read you'll get.
On burning. A 20ml sample is small, so it burns hotter and faster than a full candle and won't fill a room the way the 300ml size will.
Where to burn it. Level, heat-resistant surface, away from draughts. A breeze makes the flame flicker, which causes smoke and soot.
Never leave it unattended. Keep it away from anything that catches, and out of reach of children and pets.
