They've doubled the xp/kill and you can now spam the FoV pages for free bonus xp at the end of each one:

http://wiki.ffxiclopedia.org/wiki/Field_Manual

Make use of the field manuals and you'll be 30-50 pretty quick--even just soloing. A lot of people just do the lowman thing--make use of the xp bonus from Signet when you have less than 6 in a party, spamming pages for the bonus xp also.

***once you hit 30, kick off an Abyssea expansion. Get your cut scenes so that you can start accumulating stones to use for time in aby parties. DO THIS EVEN IF YOU DON'T PLAN TO HIT ABYSSEA JUST YET. You will want a decent bank of stones. Once you get going in there and get a little cruor and such, you can buy some abyssites/atmas to enhance stone regeneration, get better buffs, and such to make abyssea go even more smoothly.

After ~38, you may have to start scraping around to make/find parties (mostly level synch) outside of abyssea, depending on the job. A lot of players are hopping into leech spots in abyssea and shooting up to 49/50 for their subjobs or just running all the way to 90. If that's not for you, you can keep on with the field manuals and still get to 58-60 at a pretty decent clip on most jobs even soloing. After that, it can turn into a grind for the next few levels if you are having to go the solo route, but once you hit ~65 it picks up a bit and isn't too rough. The real rub is not having access to Sky unless you can make a group to get you through ZM's. FoV up there is really nice, especially on jobs that can take the puppets without much trouble. But, by then you will probly be feeling the tug into abyssea and fly right on up before you know it.