Drip candles are formulated for wax play, melting at a lower temperature than an ordinary candle so the wax lands warm rather than burning. Body shaped candles and a multi pack, all of them low temperature.
A drip candle is made for wax play specifically. The wax is blended with a lower melting point than an ordinary candle, so it liquefies at a temperature that feels hot on skin without burning it. A household candle is not a substitute for this and will cause a burn.
The sensation is heat arriving somewhere you were not watching, then cooling and tightening as the wax sets. Most of the appeal sits in the anticipation and the contrast rather than in the heat itself, which is why wax play pairs so naturally with a blindfold.
Height is the only real control you have. Wax cools as it falls, so a candle held high drops warm wax and a candle held close drops hot wax. Hold it higher than feels right, because the difference between pleasant and a burn is a few inches rather than a different candle. Test a drop on your own inner wrist first, every time, since candles vary even within one brand.
The differences are in the shape and in how much you get.
If you have never tried wax: a multi pack. Cheaper, and you will get through more than you expect while working out the right height.
If it is a gift: the body shaped ones. They look like an object rather than like equipment, which makes them far easier to hand over.
On height: higher than feels right. Wax cools on the way down. A few inches is the whole difference between warm and a burn, and it is the only dial you actually have.
On where: back, stomach, chest and thighs. Never the face, the eyes, or broken skin. Hair traps hot wax against skin and makes removal miserable, so think twice about anywhere hairy.
On cleanup: a shower takes most of it off. For the rest, let the wax cool completely and peel rather than scrape. Put a towel or a waterproof throw down first and you will thank yourself.
