You will need all kinds of sensors and switches to fully automate your house to exactly how you want it to be.
Sensors aint cheap.
Then, there is this Xiaomi who saved the world of home automation with very reasonably priced sensors. These sensors don't work out-of-the-box with your Smartthings, but it is not difficult to get it working. Once you get the hang of it, it's a piece of cake.
Motion Sensor - RMB59
Window/Door Sensor - RMB49
Wireless Switch - RMB39
Zigbee Power Plug - RMB69
You can order them through your favorite channels of buying from the China market.
According to Xiaomi, the batteries in these devices(apart from Power Plug) can last for 2 years.
In order to pair them with Smartthings, first, you will need to be as close to the Smartthings hub as possible with the sensor, your notebook and your phone.
1) On your notebook, login into your SMARTTHINGS IDE on a web browser -> https://graph-eu01-euwest1.api.smartthings.com/ login.
2) On the IDE web browser, select "My device Handlers" from the top and then click on "Create New device Handlers". Give it a name and click create, then paste the entire thing you have copied from the following. Take note that you will need to create one device handlers for each of the type of devices.
You can get all your device handlers from here
3) After you have added all the Device Handlers you are trying to add, click "My Location" from the top and then, Events .
4) On your Smartthings App on the mobile phone, go to "My Home" , under the "Things" tab, scroll all the way down and select " + Add a Thing".
5) Each of these sensors comes with a small hole, which you will need to poke it for 5 secs either with a tooth pick or the pin that comes with it to reset it and put it in a pairing mode. You can see the device reacting with its LED light when you have successfully done that.
6) On your IDE, refresh it and look for an entry that says "Catchall", it should appear seconds after you reset the sensor. Once you find that entry, mouse over the entry and you should have a String of Hexadecimal numbers that don't make much sense to you. Look out for the 4 character which I have highlighted in yellow, note that down. It should be on the 19th -22th character of the string.
7) Once done, one the IDE, click "My devices" from the top and then "+ New devices", key in as follows and click Create. Your devices should appear on your Smartthings.