Glad to hear that the Cattle Drive assignments are helping you learn java. Though the nitpicking can be a big bonus for those who pay the small fee, it's true that many people simply do the assignments to practice coding. Good for you!
It's a very kind gesture to list your tips, thank you. In this situation, however, giving big hints has the potential to rob someone of their learning experience.
Since most of the people who are doing the Cattle Drive are also doing the assignments to learn, they might actually not want to read someone else's tips and tricks first. A lot of people prefer to figure out the assignments on their own first, making their own mistakes along the way. That's a huge part of the learning process for many people. We have a pretty strict rule about not posting code in the forum for that reason.
All that to say that there's a chance that your post might get edited - or that at least the subject will be modified - so that people who would be disappointed to read your tips won't see them, or can choose not to beforehand.
Again, welcome to JavaRanch, and hope you'll be visiting often.