What do we do when our opponent deviates from joseki? The answer from stronger players is almost always "read it out." I hated this answer when I was a beginner and I hate it now. I'm not implying that there are definite patterns you can memorize for any given situation, but there are many common sequences that arrive from joseki deviation that we can learn to recognize and take advantage from. I have prepared a demo board for my favorite joseki deviation pattern. This was the first punishment I learned and to this day I am excited when I get to play it out. I hope you can learn to appreciate it as I have.
In many situation these patterns won't help. If your opponent is playing crazy moves that have no relation to the joseki you were trying to use, you don't really have a choice. You need to read it out and try to predict what will happen. It can be frustrating, but it's also good practice (look forward to a future post about improving reading skills).
Please feel free to PM me on OGS (my username is crodgers) or leave comments below if you have any questions.