It is a little tough at the moment, as most of the current generation of IoT devices don't have much security built in or are not easily updated/patchable. For the device you do own, make sure you:
- Set the password to something different than the default, preferably a strong password
- Check the vendor for patches or updates and apply them
- If you are tech savvy, only for seriously advanced users, take a look at the outbound network traffic and see if it correlates to what you expect. Otherwise your device may be under the control of someone else.
- Lastly, as you buy internet connected devices in the future, have security in mind when you make your purchase. You are voting with your wallet. Look for reputable companies who are showcasing the security of their intelligent and connected products. Ultimately it protects you.