All I've ever seen is posts about how the Dunes is a horrible place to level which is such an obvious statement for so many reasons (I won't go into why the Dunes suck, we already know) and how Korroloka is JP dominated and it's very hard to find/make a party there.
My proposal: treat levels 10-20 as you treat level 32+
How do we treat these levels differently? Where do you immediately go when you hit level 10 (for most people)? You go to the Dunes, wait for an invite or attempt to make a party. It seems like the easiest thing to do since you've already been leveling in the adjoining zones.
Now, where do you go 32+ (again, for most people)? You go to Jeuno and wait for an invite. Since there are multiple zones to level for most levels, it's a better idea to just sit in Jeuno and wait instead of waiting in a zone since you could get an invite from a totally different area.
Instead of wasting time either in crap parties, no party seeking invite, dying constantly because of new players or waiting 10 minutes for a damn spawn so you can actually kill something....why not seek party in Bastok? If you're atleast rank 5, seek party in Jeuno...Bastok is only a 3 minute airship ride away. If you get an invite into a good Dunes party, the Dunes are only a Teleport-Dem and 500 gil away.
The reason I bring this up is because Korroloka is SO much faster for leveling and I despise the Dunes, but everytime I need to level in that range, NO ONE is willing to walk back to Bastok to party, and no one is EVER seeking party in Bastok or close to airships. I end up wasting hours leveling in crap parties in the Dunes just like everyone else when this all could be avoided if everyone thought like me! Hehe^^