How to stop cats sh*tting in my front garden...

TBagpuss

remove any existing poo.

Then try one of the products sold specifically for the purpose - you can get gel which is generally citrus scented , or powder which has a garlicky smell. In my experience, both work, but different cats respond differently so you are likely to find one is more effective that the other. (I've used them in order to help train my own cats to use the flower beds rather than the gravel driveway or vegetable beds)

If you have sen the cats in the act, then a water pistol or equivalent can be very effective. Cats like to feel safe when they poo (don't we all!) so something uncomfortable and/or scary, such as being hit with water or shouted at can be very offputting.

Longer term, planting ground cover plants so it''s harder to access / dig the soil can help.

If you are finding poo on grass or which is not buried at all, then it's more likely to be a fox (or even a badger) than a cat, as most cats will, given the chance, bury their waste. I have seen cats in urban environments where there is no soil available use the grass, bit only where there is no other alternative. If that's the case where you are then you could consider making a small bed (and clearing it periodically) to keep them off the grass.

If your front garden is unfenced then dogs with irresponsible owners may also be a potential cause.

buglawton

You're an optimist about cats not leaving their presents unburied on top of lawns or borders, why else do these smell of rotting cat food?