WARNING: This is still in draft
There are four main virtues in Stoic philosophy: Wisdom, Courage, Justice, and Temperance.
Wisdom is an interesting virtue - many would assume that it's tied to inborn intelligence rather something we can cultivate. That's not true however. Wisdom is a cross-section of knowledge, experience, and good judgment.
To cultivate wisdom though, it's not enough to just have experiences. We must examine our experiences to improve our knowledge and experience in the future. That is how we can cultivate wisdom.
Wisdom is subdivided into five sub-virtues: good sense; good calculation; quick-wittednes; discretion; and resourcefulness.
Good sense, or good judgment, is the ability to weigh all options accurately.
The ability to assess an individual option.
The ability to understand quickly, which requires you to be mentally alert.
This one is similar to good sense, calculation, and resourcefulness, however it is focused on the speed at which we are able to operate. I'm sure we have all met the person who is intelligent but takes an age to reach any conclusion or talks laboriously enough to put you to sleep. Quick wittedness is definitely something that can be improved however - those who have take improv classes can attest to this. Quick wittedness isn't about being funny however, it is about being concise and decisive with our comments. To guard yourself from being incorrect however you will need experience and reasoning, and it may help to guard your conclusions when dealing with others (for example: "my first reaction is...", which gives room for you to have additional opinions). Ultimately however we are going to be wrong sometime, so the best way to be quick witted is to give up being right all the time.
To be quick witted also requires us to be mentally alert. This obviously means that impedes the alertness should be avoided (alcohol and hangovers), and activities which promote it should be pursued (sleep and exercise).
Actions: be concise in your speech, and don't be afraid to be proven wrong.
The ability to avoid causing offence or revealing confidential information.
In the stoic context, avoiding offensive actions and words is probably the most important aspect of discretion. This may seem to be contrary to a lot of what stoicism promotes - that we have little control over the opinions of others - however in actionable steps this is a simple one to follow (although not always easy).
Actions: do not gossip or talk about other individuals, especially where it may cause them upset.
The ability to find quick and clever ways to overcome difficulties.
The most obvious way to be resourceful is to be open to many different possibilities. When we encounter a problem it is a tendency to fixate on the first solution. This is a cognitive bias popularised by Charlie Munger called "First conclusion bias". A wise stoic assessed all options quickly.
Actions: consider all possibilities when faced with a challenge or problem and do not become personally vested in your first conclusion.