Do Hans COs. lv.21+ should have Mining Tunnels stuff unlock, stack those together and just knock em out from running the Tunnels maps.
Han COs reset every 22 hours after completion.
Make sure to be doing all the Koffee COs too as their available.
Do EQs when they come around.
Buy the 50 or 75% bonus exp tickets or exchange for them at the Photon Shop. Best to use them during EQs but can use them as you do COs too.
This is how it was on JP server, not sure how much of a change SEA is.