With an anniversary band, 1 to 20 comes pretty quickly solo on a mule. Fight EP, eat meat, and keep your weapon up to date, and do FoV. May as well do it on THF and go to 25 so you can flee on that mule too. ;)
If you're really crazy (or hate running your LC mule all the way to the LC guild all the time), you can go to 34 thf/17 blm. It doesn't really take all that long burning through a couple anniversary bands (we're about to get a new one in a few weeks).