At our office we have one golden rule (actually we have a couple, but this is the only one that is truly relevant!): if a colleague is able to access your PC because you left it unlocked, tough luck, you're bringing cake for the whole office the next day.
Although the imminent threat of having to bake cake should not be the underlying motivation for you to keep your laptop locked, people might have an even more relaxed approach to the subject of security while working from home. You're at home, why should you need to take any precautions? I mean, no one can order cake, so all is fine.
Well, yes, but actually no.
Why security matters
First, security is not a matter of "I don't want to be punished, so I will abide to the security rules". One must understand that you are not adhering to security rules for other people's or the company's sake, but for your own, too. It is important to internalize the value of security and personal data. You need to start thinking that you are keeping the data safe not for others, but for you. A lot of people tend to act negligently when it comes to handling sensitive information, which can have very severe repercussions
This is not necessarily exclusive to work related data, which, were it to be stolen or compromised, might lead to big financial problems to the company, but also extends to personal data. Identity theft has become more and more of an issue, due to the way many people carelessly handle their personal data online, thinking "what good is my birthday to those people anyways, many more people share the same birthdate". On its own it might not amount to much but accumulating little bits and pieces of information on a person quickly reveals the big picture, making you more transparent than you would ever have thought.
How to keep your data safe
Second, even though home might seem the most secure place to you, there are still various threats lurking in places unbeknownst to you. Your neighbor might be a super hacker, just waiting to pounce onto your information (too absurd?) or your Achille's heel might be your beloved morning coffee/tea. How so? Accidentally hit the mug with your elbow and all the work you did these past couple of weeks is gone. Backups are especially crucial in times of remote work, because you must remind yourself to do them regularly. You also have to decide which is the most efficient but also secure way for you to back your data up. There are various solutions, you could either secure the data via an encrypted external hard drive or opt for a cloud storage solution. To not grant an unwelcome access to your data via your network connection, ask your employer to set up a VPN network. This way, you can use the VPN to gain access to your secure office network without having to physically go to the office
Care for analogue data too!
Third, do not forget that analogue and digital security are equally relevant, even at home. Only because you have got a VPN network set up and the access to your PC is protected by a password, it doesn't mean you are adequately protected, if you leave papers with sensitive information lying around in the open. It is essential to store sensitive data in lockable containers, where it is not openly accessible for anyone and everyone.
Stay safe everyone, not only physically but also in regard to your data!