I don't spend a ton of time on the forums, but I am loving this AP so I thought I would add a few thoughts.
I'm running three Play by Post tables of this currently.
Here are some things I have done.
Before we started, I showed the players a list of other characters in the charter while they were building their characters (not the actual list from the AP as there are spoilers there) so they could choose to create characters with possible relationships to the NPCs.
One example is I have a player playing an older Nuar that has known the Hardhoofs for years. Another table, a player wanted to play a Drow noble that has fallen from grace on Apoostae and is using this expedition as a chance to restore their reputation. He asked to have the Engellos sisters be a family in service to his house, which has caused all sorts of fun as the first book plays out.
Read ahead as much as possible and pick up on character traits or possible hooks from later in the AP to bring the charter characters to life. Play up the Hardhoof bickering from the outset, mention Ta-Yeta's sweet tooth etc.
On a table that chose to share the information on the Stone Needle with Plaustov, in the spirit of open sharing of information, Oskanna called to mention the anomaly within their territory they intend to explore once they get through their first winter. This is table setting for Book 3 once we get there, but has been mentioned very early on so it will feel more organic than Threl showing back up out of the blue.
Good luck with this, it is a very fun AP