The easiest way to almost guarentee a prize in the mystery box game is to pick one box and click that box on all 8 of your daily turns. After trying this i got at least ten thousand TU.
Easter Egg - moreTU:
A trick to get more TU is if you manage to find somthing of some value such as a job token you should donate it to the dump in relcore you can get at least 500 TU, then if you use your one withdrawal to take it back out again you can donate it again to get the same money all over again.
An easy way to get tu is by the toy quest. You can sometimes get up to 100K everyday by playing this game. Also visit the enchanted springs,that also sometimes gives you 100K. A way to make millions is by buying credits wich supports the site and keeps it running. Buy something from the credit shop (Say kioka eggs, Omni eggs or Liyure eggs, they sell best) then sell the items to other users, you can get millions from those items, it's a great way of making to and supporting the site.