I leveled up really quickly by at level 31 going pure trader and then, when I had enough sp, I increased leadership and I could do a lot of high exp jobs, earn a lot of cash and get many dailies completed. Then I moved onto an all jobs build and was earning 4-6k exp per day completing all the daily quests and doing the odd exp job in between.
A key factor though is the sensible use of level ups and to set jobs up before leveling so you don't waste energy. I think I slept for 7 hours in the hotel in my first 35 levels and I didn't use any energy buffs or premium energy reloads.