Here are a few tips on how to remove candles from their holders.

Votives:

Votive candles can easily be removed if you put a couple drops of water in the bottom of the candleholder before placing the votive inside.  The water will remain after your candle has burned away.  You will easily be able to pluck the remaining votive out in one piece!  If it is being stubborn, allow the candle to burn down a little more and then wait for it to cool off and try again.  If that still won't work, freeze the holder overnight and then carefully poke at it with a strong butter knife.  You need to be very careful with this as it is easy to shatter the glass this way.

Wax tarts:

After you are finished melting your tart in your tart burner, put the whole thing in the freezer for 2 to 8 hours.  The wax should pop out nicely once it freezes as it will shrink.  You may need to use a spoon to give it a boost.  When shopping for a tart burner, look for one with a removeable top, so just the part that holds the tart can go in the freezer.  Additionally be sure to completely thaw your burner before reusing it.

Kristine's Candles and More