Establish clear rules for family (partner) interruptions at work.
Depending on what you are working on, an interruption can be a non-event or it can wreck hours of investigation. Our focused concentration at work is often not obvious to our loved ones. Explain to them the potential cost of an interruption and agree on a method to help you both get what you need.

In my case, if my wife needs something from me she enters my office silently and waits until I acknowledge her. I always see her and know she’s there. If I’m deep in thought and can’t be bothered either I shake my head or she gets the picture and quietly leaves. Most times it’s just a matter of waiting a minute or two while I finish a piece code or a communication with the team. Figure out some way to ensure you are able to concentrate on your work in a collaborative manner.

Reserve time to decompress after work.
After work, many of you (used to) commute home. Most of us regard a commute as painful but the time between work and family is valuable for decompressing and reviewing the days events before coming home to the fun of family. When you work from home your “commute” is typically the ten seconds it takes to leave your office and enter the living room. As a result, you don’t have a chance to blow off steam, to relax, to let the weight of work slough off your shoulders.

Please make sure you reserve some time after work before family for yourself. Take yourself (and your dog!) for a walk. Workout. Ride your bike around the neighborhood. Soak in the hot tub. Whatever works for you, just try to let your mind relax and your family time will be more enjoyable.

Don’t work too much.
Yeah, yeah, you’re a go-getter and all that, we understand, but we also want you on top of your game every day. When working from home it is easy to stay way late at the keyboard or on the phone making things happen. Be very careful, it’s extremely easy to get burned out because you care so much you work too long. Life balance is critical, don’t overwork.

Avoid answering the home phone while you are at work.
Would you answer the home phone if you were at the office? No. Don’t answer your home phone, don’t listen to the voicemail message. (Of course you’ll answer the call from your spouse saying they’ve safely arrived at their destination, but even then keep it short.) Try to minimize non-work activities during your work hours at home.

Get a good office chair. I use a Herman Miller Embody, everyone has a favorite. My bet is your home office chair is inexpensive and good office chairs are pricey. Nevertheless, since I sit in my chair many hours each day I feel this is a worthwhile splurge expense.

Get some kind of standing desk. I am very happy with the inexpensive Varidesk Pro Plus 36 https://www.amazon.com/dp/B00JI6NCCK atop my regular desk. It's super helpful for day-long desk jockeys. In my case the Pro Plus 36 model supports a 27" iMac and an external 27" monitor just fine.

Have a large water container at your desk.
Hydration during the day is key. Move around. A standing desk makes that a no-brainer. Look out your window, change your eye focus. Walk around the house, say hi to your dog. Go outside and smell the roses.