In my candle burning experience, candles are best when it comes in it's own container. That way the recipient can just light it up and not have to worry about placing it in a holder or fire-safe container.
I like to scrape down the sides as the candle burns, that way, I can ensure there is as little residual wax as possible. When it burns down to its metal base, you can just pick up that little bit left over and throw it away.
I filled these miniature pails with Lavender scented wax and decided to leave it in it's purest colour - white. After burning, you can fill these pails with sand and put pillar candles in or stick these adorable popsicle candles in.