Full awareness, training, and discipline by all hands is essential. The force transits to its objective area in complete electronic silence. Broad surveillance systems are known so any detection method is countered either by denying sensor information, misleading, or providing expected results consistent with something else. For example, ESM systems rely on active emissions from radars or communication systems. So nothing is radiated.
Overhead systems are in known orbits, are predictable, and their sensing capabilities known.
Surface search radar identical to commercial ones are used. Turn count masking is used by the ships. Aircraft maintenance on the CV and other helo equipped ships is limited to prevent transmissions. One night in bad weather a man went overboard when the ship was within 200nm of a Soviet airfield in the Kuril Island chain. Despite launch of helicopters and active search methods by several ships in the successful SAR, including clear voice UHF transmissions, the force is not detected because no Soviet asset was above the radar horizon.