A few things I have learned thru tons of reading, and having a new one to finish litter training as well.... Keep your litter box in whatever corner of the cage he seems to like, put his pellet crock/bowl right next to his litter pan(maybe between the pan and the cage wall) so he has to hop in to eat, or if its a hay rack/pellet feeder, hang it from the cage wall right above his box. When he does poop/pee outside of the litter box, pick it up with some tissue and put it in his box so he sees where its supposed to go. Along with any pee soaked paper. Don't expand his area much past his cage (they say a few days to few weeks) until he gets the gist of using it, and then you could let him out more frequently. Also adding another litter box or two around the area you let him out when hes not in his cage, for accidents and the like. I personally have only had mine 2 weeks and I let him out in my living room, and the first few days when id notice a dropping or two, id put him back into his x-pen and put the poop in his litter box. After a few days he got the hang of it and now when im home after work, or before work, he has a good 2-3 hours to run around before bedtime, and I gotta tell you it has been pretty easy!