Start by crushing the juniper berries and coriander seeds lightly, either using a mortar and pestle or by gently rolling them with a rolling pin.
Combine these crushed botanicals along with the chamomile flowers and any other herbs and spices into the bottle of high-proof vodka.
Seal the bottle tightly and store it in a cool, dark place, allowing the botanicals to infuse into the vodka for around 24-48 hours.
Taste the infused mixture after 24 hours and decide whether to continue infusing for a more pronounced flavor. Steeping longer can result in a stronger flavor profile.
Once satisfied with the flavor, strain the mixture through a fine mesh strainer or cheesecloth to remove the botanicals, collecting the infused vodka in a clean container.
Optionally, you can let the gin sit for a few days to mellow the flavors before using it in cocktails.