Calling all the Divination wizards out there. I'm curious what your strategies are for using your Portents -- specifically, mediocre rolls right in the middle, rather than high or low rolls on your d20s.

For the purposes of the poll, let's say one of your Portents for the day is an 11. How are you most likely to use it?

On a concentration save, if it’s 10 or higher.

Quote from SeanJP >>

On a concentration save, if it’s 10 or higher.

Oh, good call

It depends on what the rolls are.  The diviner in our party rolled a double 20 today.  If either of those dice go to enemies we are going to kill the diviner after we kill the enemies.  More than likely those will be saves or Paladin attacks.

You almost always know whether it will succeed or fail before you use it, either because it is really low or high or because someone else in the party already passed or failed.  If Bob rolled an adjusted 15 against the dragon breath and passed then you know the Rogue who has a 18 dexterity will pass with an 11 portent.  If Bob failed then you are not going to use it for that. 

If the enemy rolled an 11 to hit and missed then you know he will miss on an 11.  If you cast fireball last turn and they rolled a 9 to save and succeeded then you know 11 will succeed as well. 

Although I DM most of the time, about 70%+ of my 5E playing time has been in a Div Wizard.   But it took a couple of days for me to decide to reply.   Here are a few general notes: 

1)  You roll your portents first.  I don't have all the cites handy, but spent quite a bit of time confirming this.   My morning order is to roll portents and then prepare spells for the day.   This means I make decisions on what to prepare based on what portents are.  If both are high, I favor spells with a to-hit and avoid Con saving throws (con is generally the highest save state in the MM).  

2)  I can't answer this questions because it's situational.   I can say "yes" to every item on your list and add a death save, concentration save, etc.   It's all up to what we encounter and how the battle develops.  I might have two natural 20's for portents and love to give them for critical hits, but then fate will step in and it's my save v. dragon breath to avoid dying.  Or a concentration check that can't be missed.   See #3

3)  I use three large D20's that I roll in front of the DM at the beginning of day or session.  I let them sit next to my dice tray.   It's a constant reminder every time dice are rolled to add to my mental checklist if I should use one.

There's a famous axiom that no plan survives contact with the enemy.   Portents are OFTEN reactions to what you cannot expect in your plan.  

My rule is to use them for maximum impact and don't end the day with any unused.   

I also use them all the time in non-combat situations.

I am the shmuck (Charisma penalty) that always seems to get a good deal with the tax collector who comes around once a year.