Don't skip the hard verses. Dig in and let the Holy Spirit give you understanding. John Piper breaks down 1 Peter 3:19-20 while outlining the process he uses for decoding confusing portions of scripture.
1. What parts are clear? Mark them.
2. What's the main point?
3. What is the context? Do words or phrases match other parts of the chapter or book?
4. Does it reference other parts of the Bible?
5. Use a well trusted commentary.