Uh... Doesn't the XP get shared anyway? I think that IF you try to overstep your actual level , ( Say for instance you try to do +40 when you are only around 28 or so..), Then you wont get as much XP from that run. My advice? Try to run up as many client orders that are relevant to the quest your doing.
For example:
The easiest way is to accept a quest, then press the ESC button. Find "Client Orders" in the menu that pops up (forgot exactly where, just look through all the icons). Click on it, and a window pops up with an option to see accepted orders or recommended orders for the quest. Click on the latter option and a list of client orders relevant to the quest will pop up for you to accept. ( I really don't remember how many you can accept at any given time.)
So then , Go questing and even in a team, you'll be able to knock thru those orders in no time flat and then when you return, you get TONS of XP and sometimes some other goodies as well.