Common sense suggests the best way to get good work done is to try and be in a positive mood, but The Wall Street Journal points out that it's not always the case. Sometimes, a negative mood has benefits too.
As you can see in the chart above, your mood affects a lot of the decisions you make. Being in a good mood is excellent for being creative, but a negative mood can actually make you more attentive. Knowing what types of negative components might come with a mood can help you prevent them from happening.
For example, if you're super cheerful one day and try to just dive headfirst into a project, the Journal suggests slowing down a bit to seek out more information from co-workers before proceeding (bonus if you find someone in a negative mood to rein you in a bit). Conversely, if you're in a negative mood, recognise that you're prone to close-mindedness, so try not to shut down ideas immediately. Obviously the specifics are a little different for everyone, but it's something worth keeping in mind as you move throughout your day.
How Being a Worrywart Helps at Work [The Wall Street Journal]