Getting the terrain right for Auldearn might be trickier than first seems. Although the battlefield is on gently rolling countryside, what you can see on foot is a lot different from what you expect to see from a map or satellite image. Two to five metres elevation hides a lot of things so a lot can happen between a couple of contour lines. That being said, this map from Historic Scotland's battlefield archaeology team is a good start.
Ordanance survey maps are still some of the best maps in the world getting the right amount of detail with excellent clarity. In addition, Historic Scotland did some soil analysis and identified areas of alluvium - pinpointing areas of marsh which have since been drained.
The oldest map of the area I could find was General Roy's from 1746-7, one hundred years after the battle. In the century since Auldearn, new farming techniques had begun to reclaim land by defining surface drainage through better control of the natural stream systems. However, on Roy's map, areas of marshy ground can still be seen.
If we look at the image on GoogleEarth the areas of poor drainage, tied to the presence of mapped alluvium still show up
By simplifying the ordnance survey map, highlighting the contours and shading them, placing on streams and alluvium, the general shape of the old village, the battle field begins to take shape. Garlic Hill points like a dagger into Auldearn, showing how Hurry could have over the course of a days fighting begun to suffer from "target-fixation"!