The better leveling method?

I know guildleves are generally the best SP for what is being offered, even after the nerf, but outside of that, what would be the best method for solo grinding? Should I be out searching for mobs 7-10 ranks above me for the big burst of SP, or should I be focused more on grinding mobs lower than that, which give less SP, but I can feasibly/supposedly kill faster?

I'd like to say that my downtime killing higher ranked mobs isn't bad at all -- with Absorb MP and DoTs running, I wind up killing things without blowing much MP on nuking; it's more a matter of keeping myself healed so I don't get 2 shot. XD More even ranked mobs I can kill in like half the time, but the problem is I tend to run out of mobs before long, which means that even without requiring downtime, I still wind up having it. Thus far, I've been messing around in Coerthas around Camp Glory, killing some crabs in La Noscea, and killing those evil flying jellyfish mobs in that one cavern (I'm brainfarting on the name).

I realize those mobs probably aren't the most SP efficient, but it's difficult finding an area with a consistent enough level range that I can feel like the grinding is worth it. Does anyone know of any decent camps for the 20s-30s that I could rank up on?

At rank 30, kill efts in Mistbeard Cove, Tam Tara Deepcroft, or near Camp Nine Ivies.

At rank 35+, kill the efts to the East of Treespeak

At rank 40+ kill the raptors at Boulder Downs, or North of Camp Glory.

(do it in a party of at least 3-5)

You can stay in Nanawa until rank 27 and then puks in Coerthas to 31. Duo or trio is good with at least one melee class.

If you really want to solo it will be difficult to find the right mob for you. Some mobs are easily killed with lancer while others can be killed with little effort by archer. For pugilists for example it's best to go after skeletons. Other nice mobs are all kind of ahriman(lancer), drakes(gladiator, thaumaturge), raptors(pugilist, lancer, gladiator), salamander(any), basilisks(lancer, gladiator, archer). That's only what I tried to grind solo though. If the mob is 10 ranks or more above you, you get 450 or 600sp which gets less and less with every rank you get closer. Once your rank is higher than the mobs the sp drops dramatically.