Generate a really accurate map/plan of your grounds and house

[d000hg]

String and pegs is fine when it's fairly flat, accessible ground with good sight-lines. When there are elevation changes it's harder to tell the string is straight, when the going is hard then getting to each point to measure is harder and you may struggle to tell if your grid is regular when you can't see far. Still, got to be worth a go. A really good aerial photo would be handy but that probably does require a drone.

[vetran]

String and pegs is fine when it's fairly flat, accessible ground with good sight-lines. When there are elevation changes it's harder to tell the string is straight, when the going is hard then getting to each point to measure is harder and you may struggle to tell if your grid is regular when you can't see far. Still, got to be worth a go. A really good aerial photo would be handy but that probably does require a drone.

get a light strip of wood - roofing batten or similar, add notches 1m apart. rest on string to test spacing. Measure diagonals.

Depends on your level of accuracy.

I had a garden on the edge of a quarry about 6 feet variation in levels strewn with concrete, we got it flat & built walls around the dips.

[vetran]

https://www.allaboutcircuits.com/new...er-landscapes/