There are many ways:
1. Buy some cash shop items and sell them. (fast but maybe also expensive )
2. Sell your drops
3. Sell your LAK
4. Spend as less money as possible
5. Work as a Pet Level Service.
5.1 Buy level 1 Pets cheap and sell them on Level 60 or even 115 with some provit
5.2 Find somebody who gives you his pet + Money + SS + Craker for a true level service
I do a mix of way 3 and 4.
e.g. I don't chip the Mobs when I farm, so I can sell most of the LAK.
This means I need a bit more time to kill the mobs , but who cares if you can do other things during that time with the right tools