For the kids, a microadventure does not have to invole a whole lot of preparations.
What I have learned is, that the tough part is to get from inside the house to the outside of the house.
The rest will take care of itself.
One thing that is very nice to have, that is some kind of snack for the kids. To keep them going out there or to even persuade them that your idea of a trip to the local forest, beach or field is a good idea.
On this occasion, we used the bikes to get to the local forest. And I brought one familiar object, the hot chocolate. We played with another familiar object; a stick or two from the bottom of the forest.
And the adventure part of this trip was a small child-friendly binocular, with which the kids had a great time spying on some animals.