We have three cats, two male neutered and one female (neutered). Since little cats arrived (they are Feb birthday) the neighbours have said their front doorstep has been peed on, and their garden is being descecrated (lots of neat flowerbeds with bare earth). We have a garden too, but a bit wilder perhaps.
Neighbour has a two year old and is pregnant; also they are not very keen on cats anyway. I understand why it is horrible for them. I used to suffer the neighbours' cats using our sandpit/lawn etc when my dcs were small so I feel her pain.
Soooo...how do I change our current cats' habits? I've explained there is a rogue unneutered tom around who is probably doing the spraying on their door step and bins, not our cats, but I can't see how I can ban our cats from wandering where and when they please. Her other objection is that they are stalking birds and climbing trees: I really cannot do anything about that can I?
Cats are hunters.
First step is I've re-instated a litter tray in the house. Should it be two as we have three cats?
Second step is, I'm not letting them out the front door anymore (maybe if they go round the back, it will be less of an invitation to use the neighbours nice front garden 
Third step is, perhaps install some pheremone in house in case our older cat (3 years) is suffering stress?
I want to be on good terms with neighbours, but also to make it clear to them that CATS ARE CATS.