I had a lvl 25 orc raider, and soloed him to 35 in about 2 and half days. I used a Tarbar/Brig armr and NON-STOP D-SS.
Head to dion, stock up on D-SS and buy a good bow/arrows. Now, head to the hideaway and towards where Lord Nuraka spawns. In that immediate area is an NPC named "The Herald", immediately S/S-E of him, there are 2 huts in a half fenced in area.
This area spawns 3 Ol’Mahums, they are a quick 30 second spawn and extremely easy to kill. At lvl 25 i was like resting during their respawn, and it was non-stop XP. THey also drop around 350a. At level 30 I was making a lvl every 5 hours 🙂
At lvl 25: I was getting 1800xp/80sp when a lvl 36 elf archer was getting 1700/70ISH on Wyrms.
At lvl 30: I was getting 1700xp/70sp x 3 every 30 seconds – NON STOP
NOTE ** When they are low they do run away, so yank out that bow and drop them. This is the best spot in the game. I have 8 alts all near lvl 30 and found this to be the best NON-exploit i could find.
The reason they have so much exp/sp is that they are double HP of a same lvl mob… so even if they are GREEN and MISS you more often you get more EXP/SP than a yellow or red ^_^