How do I find, identify, mark, etc rabbit warrens?

How this job should be done depends on why it is being done.

For political reasons, it is great to have all rabbit habitat recorded and shareable - this is done using Rabbit Scan but not what everyone will want to do.

For monitoring purposes on large holdings, spotlight surveys are ideal for comparative monitoring of rabbit populations - not so easy on small blocks.

For contractors, so they can quickly see where to work, Rabbit Scans or flags inserted at warren entrances are really useful,

and sometimes it is helpful to use night-vision cameras to check live movement in locations of interest.

Thus, there is rarely one way of doing rabbit work and choosing what will work best in the circumstances is a very good way to go!