Good question. "think" is about opinion. "find" is about experience. This sentence below contrasts meaning of the the two verbs: "I used to think that dieting was a waste of time and that I would hate it. But recently, I have tried dieting, and I have found it much more helpful and rewarding than I had originally thought."

Generally, people use "I find," when they are basing a statement on their own personal experience. For example "I find that Turkish people struggle to use articles correctly in English." But if you are talking about something in the future, you will have to use the verb "to think." For example "I think that you will feel better tomorrow."

In my humble opinion, we you say "I find..." it means you definitely know something about what it is in question. For example, if somebody asks you about a book that you have not read, you should not answer with "I find it...". But you may answer with "I think" if you know something about the book from other people who read it.