Very low levels are done solo these days. I solo'd DNC up to 42. That said, you can usually grab a level sync party in Qufim island (level sync allows you to drop a party's level to the level of an individual in the party, so that a group with a 56, a 37, a 45, a 40, a 22, and a 20 can all magically become level 20 for the duration of the party, and earn exp at the level 20's rate.) The next "good" camp is now East Ronfaure [s] at 35, so you may have to sync down to Qufim or solo in the patch between 25-35. Again, it's not so hard - the amount of exp per mob has been increased, and with Fields of Valor giving you an extra few hundred exp an hour and buffs, plus exp rings that increase the amount of exp per mob, you can solo an entire level in an hour if you're really determined.
These days, at level 30 you can pop into Abyssea and do Bastion solo, depending on the job. Anything that can cure can get a few hundred or even a few thousand really easy exp. Level 30+ can alos "chest leech" in Abyssea, although that method is generally employed by folks with multiple 85s that have maxed out merits and have a lot of Abyssean cruor to burn. I ran SCH up from 48 to 85 in about a week that way. I don't recommend it for any job that you don't already have mostly capped skills for, since it can take months to catch skills up if you skip the grind.
Moblin Maze Mongers allows you to avoid the tedium of finding a camp and just sync to a custom crafted maze filled with your choice of monster. MMM's sweet spot is between levels 25-55, since Qufim takes care of 20-25 and you can do other things post easily 55+, such as pink birds at the leypoint.
Level 50+ also has the option of Campaign battle for solo exp, although these days Bastion has taken over as the solo battledfield poison of choice since it gets more exp.
All in all, SE has given us a great many more options for exp. It's still a slow tedious grind to level 30, especially the first time around, but it gets better quickly.