Let's start off with the basics. For a good yard I suppose the defence towers should be place randomly, so that every corner is covered. The town hall and resource harvestes should be kept close with a bunch of defensive towers so that they protect your yard from being looted. For example take this yard:
It has a greater risk of being looted than this one here: This is because in this yard defensive towers are randomly oriented and in yard A, they are noth. Also you will see that in yard A, the harvesters and Town hall is kept very close to the defensice towers. So if 2-3 towers are destroyed, the resources are totally exposed to the enemy. If you want you can make layers of different typpes of buildings, like:1st layer:Town hall2nd layer: Harvesters and Silos3rd layer: Other building like Monster lab and all.4th and final layer:Defensive towersBut keep in mind that 4-5 defensive tower should be in layers 1 and 2 also, so that if the 4th layer is destroyed, there is still some hope of surviving.Thats all for now!I'll be back with more tips for your yard. Until then, stay tuned!