1. Get started early like you would for the office
When working in an office, your morning commute can help you wake up and feel ready to work by the time you get to your desk. The mental association you make between work & the office can make you more productive, but there's no reason to lose that when 'WFH'. So make sure to set your alarm and wake up with time to follow your usual morning routine (shower/ get dressed/ breakfast/ coffee). It'll help get you in the right head space for work and give you the time and space to prepare for the day, both mentally and physically.
2. Choose a dedicated work space & keep it tidy
Try to dedicate a specific room or surface in your home to work that has enough space for you to work comfortably, ideally with your office chair to provide support. By having this specific work area, you'll be able to keep your leisure spaces free to relax after work, making the work-life divide a little clearer. It's unlikely you'll have a cleaner at home like you did at the office so make sure to tidy up after yourself!
3. Communicate expectations those others in the house
Just because you're working from home doesn't mean you're available all of the time and it's helpful for others in the house know this. You might decide that wearing headphones or shutting the door is your signal to them. It's especially important if you're speaking with customers or having a video call, let alone if you just need some quiet to focus on a particular piece of work.
4. Take clear breaks & interact with other humans
Don't let the weirdness of working in your home prevent you from taking time out. If you were in the office, you'd be getting up to make a drink, catching up with colleagues or having a chat around the water cooler before returning to your desk to crack on.
So rather than just opening YouTube or browsing the news, use your breaks to get away from your desk. Walking around the house, moving to another room or getting out into the garden is a nice way to break up the day. Also, you're working from home, not the moon. Interacting with other people during the day is allowed/encouraged! Spending time with others who might also be at home is a great WFH benefit so make the most of it as well as video calling with friends as they're most likely working from home too.
5. Balancing work & home
A benefit of WFH is that the time you spent driving to the office can be spent on putting some washing on, setting the dishwasher off etc. You might decide to extend your lunch break some days to spend time with family and instead work a little later to make up for it. This is a healthy balanced approach... the operative word being balanced. If you meet your objectives, fulfil team goals and remain responsive during work hours, you are just as productive as you were when in the office.
6. Pick a definitive finishing time each day
From what you've just read, you might be under the impression that working from home instantly establishes more of a work-life balance, but be careful with that assumption. Working from home can also feel like being at a casino, you can get so caught up in your activity, in a relaxing environment, that you lose complete track of time. Now you don't have your team packing up around you and leaving the office to remind you to do the same, so make sure you have something to indicate your normal work day is coming to an end. You don't have to stop at exactly that time, but knowing the work day is technically over can help you start the process of shutting down and calling it quits for the evening. Overworking can be a real issue, so clearly define what hours you will be working and stick to it.