Running a business including both domestic and international clients from my home for 15 years, I've had a lot of experience in the whole work from home paradigm. [I live in the San Francisco Bay area so I'm under shelter in place orders as I write this, but it doesn't make much difference in my days except that I can't train Brazilian Jiu Jitsu at the studio.]

 Doing it all from home is a different beast from the occasional day-a-week kind of working from home.  It can be hard to organize and very isolating, even if you have a house full of family to keep you company.

If you're embarking on this journey, I have some tips that may help save your sanity - or at least your productivity.

1. Lists.  Lists help keep you on track when it looks like an open ocean of time.  Keep a list - updated every day - of what you want to accomplish today.  Since you're working at home, adding the things you want to accomplish on the home front can help you get organized and see the big picture.
2. Routines.  When you're going to work you have a time you get up, a time to shower, you pick out clothes, you get the kids up and going, leave by a certain time, and then you another whole routine to guide you when you get home.  When you're at work you have meetings, breaks, lunches, and other things that build structure into your day.  When you work at home all the time it's really easy to slide into getting up late, spending the day in your pajamas, and wondering at the end of the day what you actually did all day.  Obviously your routine will be different now - for example, no commute - but keep as much as you can and start building in the rest.  Have start, stop, break times.  Be sure you take a shower and get dressed every day.  If you spend time at the gym, schedule in that time at home (there are lots of services streaming all kinds of workouts for free right now, or get yourself some exercise videos, or just head to youtube workout videos for a period of time every day.)
3. Set up a work space.  If you're working from the kitchen table you're going to be competing with everything else going on in your household.   A folding table in a corner with some power and chargers is plenty; you just need a place that you can maintain without setting up and breaking down daily, where you and everyone around you knows you'll be working.
4. Keep in touch with your work colleagues.  Email isn't going to help much with the isolation; if you're not already using skype, slack, zoom, webex, or some form of audio/video conferencing,  now is the time to start.  Be sure you have audio or video contact with at least one colleague every single day.  (Put it on your list, add it to your schedule.)  Video contact is better - if nothing else, it helps get you out of your PJs.
5. Coordinate your schedule with others in your household.  If you have one exercise bike and two adults, better to schedule different times so you don't get off track.  If you have kids at home with you, coordinate your schedule with theirs and with other adults in the house. If you have school-age kids at home try to coordinate with parents of their classmates - one parent could lead an internet discussion, teach a subject, or just monitor online for an hour and then trade off with other parents.
6. If you're a project manager, manager, or team leader:
1. Check in on every team member every day.  A call or video would be ideal but that gets hard if you have a large team.  In that case, have yourself a schedule so you touch base with each person individually via audio or video on a rotating schedule. 
2. Use video conferencing for team meetings.
3. If you're not talking to a team member on a particular day be sure to check in on instant messaging or text.
4. Keep your group meetings intact (making allowances for folks who are dealing with children at home - change times if you need to).
7. Take breaks.  Either schedule them in or put them on your list.  Do whatever you'd do on a break at work - take a walk, read a book, get a snack.

A little organization can go a long way. Watch my website for more tips and tools.

Be careful out there.