Residence can be created in multiple ways. This ranges from a manual selection of the area to automatic creation when you place your first chest on a ground.

Manual selection

Select the residence selection tool, which is a stick. You can double-check the selection tool with /res tool command. 

While holding the selection tool in your main hand, select 2 opposite points with left and right mouse clicks. After clicking with left mouse, you will get feedback message similar to

After selecting the priamry point, go to the oposite side of your residence and right-click block. This, again, will output similar feedback message

After selecting 2 points you will get additional message into an action bar with a size of selection and how much will it cost for you to create a residence like this.

In addition to this selected are will be shown with particles to indicate exactly which area gets protected after creation. 

In case you are not happy which area got selected, you can reselect points or use commands like /res select expand [amount] or /res select contract [amount] to contract or expand the selection to the direction you are looking at. So you can tweak selection to your own liking. 

After you decided that selection is correct and encloses the entire area you want to protect, there is one last thing you need to do. You will need to perform /res create [resName] command. So if you want to create a residence with the name of SweetHome then the command will look like /res create SweetHome after which you will get additional feedback message with extra information and protected are will get marked again to indicate what exactly got protected. 

And you are done! You have your home protected from griefers and you can be safe in this area.

Selection does have additional variables which can help out to select an area to your liking, so check out commands section. 

if you are too lazy to select an area by hand or its too complicated to know where your residence ends and where it begins, you can use /res select auto command which will toggle automatic selection depending on where you move. So after turning this on, what its left for you to run around your residence from edge to edge and area will be selected for you while showing with particle effects what exactly got selected. 

Auto Creation

Automatic creation has a couple of variations by itself. So let’s look at the first one. 

Stand in the middle of your house, ad perform /res auto (resName) (radius) where residence name is optional and if not provided will use players name. A radius is an option too, but you can provide max size of residence you want to create. This command will create a residence as big as you can have around you by taking into consideration any residence which would overlap each other. 

Another option is to get your new residence by simply placing a chest on the ground for the first time on a server. This should be enabled in the config file and it can give out new tiny free residence or charge player accordingly if needed.