A slow safari is mostly walking and waiting, so everything you carry should be quiet, dull coloured and comfortable for long hours.
Clothing: olive, khaki or grey. No white, no bright blue, and nothing that rustles. Long sleeves and full trousers for the walks, a warm layer for early mornings between November and February.
Feet: broken in walking shoes, not new ones. Two pairs of socks. Leeches are a real thing in the Ghats during and just after the monsoon.
Optics: bring binoculars if you have them, 8x42 is the sweet spot. A long lens is nice but a pair of binoculars will give you a better trip.
Leave behind: drones, speakers, strong perfume, and any expectation that the forest owes you a sighting.