Now that you've soldered the tail together snip the bottom off to even it if needed. Use your file to round the end of the tail and to even out the so...
Step 4: Soldering
I won't go into how to solder since Mrballeng has a splendid video on how to do it!
I will say it is best to lay your pendant face down since it will allow you to get a good bead on the back side and leave the front still pretty flat.
I used the same technique of pounding my solder flat and snipping off pieces.