We cut ours at the end of every month - that way we don't forget and it seems to be regular enough for our goats. Get all the mud out - you can see quite clearly the nail curling round - it's papery - cut this bit off a leave as flat as possible - we have a bucket of soapy water to give each foot a clean and a nail brush (human kind) to give them a bit of a scrub and an old tea towel to dry them off before spraying each one with an antiseptic spray (purple coloured - it dries like a film on the hoof, for horses too). We spray them whatever, even if the foot looks good. Each goat takes about 10 mins and my OH does the cutting while I hold the horns to stop them jumping around (useful to have the horns doing this!). It's always under duress! But we keep dried apricots which they devour as a treat afterwards so they think we're nice people again. Do their feet regularly - it must be one of the most important procedures in goat husbandry, have a good routine and make sure you get in between their toes too, quite often problems start there.