One of the benefits of being part of a practitioner community is that we can learn from each other. Here are some assorted tips and tricks from N2D Method practitioners, specifically related to JTBD.
Mentally prefix with "I want to..."
Before writing anything down, mentally prefix the JTBD with "I want to..." and then add the job they're trying to accomplish. So, if your JTBD sounds like "[I want to...] watch a movie", the only bit you need to enter into the Method is "Watch a movie".
How many JTBD should you have?
The more JTBD you use, the longer the process will take. 20-30 seems to be typical but it really depends on your project and how fine-grained you wish to be. If you have many more than 30, you may speed up your workflow by trying to identify themes or similarities and merging some of the JTBD. Another technique is to use the 5 Whys technique to get a higher level, shorter list.
Don't mix business objectives with JTBD
The N2D Method helps you to discover how the organisation can meet its objectives by serving the needs of the people it cares about most.
It's possible to end up with JTBD that are actually business objectives. For example: "I want us to sell more garden gnomes" isn't really a JTBD that someone has. It sounds more like a business objective - Sell more gnomes i.e. something the organisation is trying to achieve. By adding the word "us", they are speaking on behalf of the organisation, not as an individual.
It may be, however, that one of the groups in your project is travelling gnome salesperson. In which case, perhaps their specific JTBD could be rephrased as "Sell more gnomes".
Keep it real
JTBD tend to work best when they're practical, achievable things. Something you might be able to prove that you'd help someone achieve. So, if you have a JTBD like "Be transparent" or "Be open", you may want to be more specific. How might that person attempt to be transparent or open? What is it specifically that they are trying to do?
A mental trick you can use when writing JTBD is to think about the later stages of the Method. Specifically the Initiative Scorecard. Pretend you have an Initiative, like “Give iPads to all staff”. Then say “if we gave iPads to all staff, what impact would that have on helping people to [the JTBD]". If you struggle to answer the question, as you would here if the JTBD was “Be transparent”, then it’s a good sign that the JTBD should be more specific.
If your answer is "It depends" or "I don't know", that's a good clue that the JTBD needs to be clearer.
Keep JTBD singular
Just have one thing in a JTBD that the person is trying to accomplish. If you have a JTBD something like "Buy popcorn and watch a movie", that's two JTBD joined by an "and". Get rid of the "and" and create two separate JTBD.