Leave our warrior fortified to handle an oncoming attack.
The one problem I see with this is that both cities will be able to bombard the warrior. At the time I placed him there, he was in a great position to target units. I failed to consider the snafu he's currently in. My apologies.
Aldor's suggestion of moving the scout to the forest for a defensive position is a pretty good idea too.
My original intent was to keep the scout there up until the attack, so we could keep track of what was going on. I agree moving him out of combat, though I would keep him close by to watch areas that we don't have LOS in. One trick I've found that often works is placing my scout on lux resources, as the city tends to target them.
F
rom Metho's prior tips all level gains should be saved. After puppeting the city all units should heal up and defend against and exterminate remaining enemy units, before positioning for the attack on the next city.
Saving up promo's for insta-heals is definitely nice, but not required. If you strongly feel the need for a certain promo, or it looks like an insta-heal won't be needed, then go ahead. I've just found that insta-heals are very handy.
While I can agree on healing up for the next assault, try not to take too long. Just in case they make more units.
Also, please take several screenshots so that all the other players can see how our first war went. If you're able.
Edit: Play when you're ready, Centerfinger.