On Chabad's website, important tips were published regarding this year's Yom Kippur observance as follows:
1. Brush Up on the Laws
Since you won’t have a rabbi or friendly pew-mate to address your questions as they arise, be sure to stock up on all the info you need in advance. Here are the absolute basics: For the nearly 26 hours of Yom Kippur, we “afflict our souls” by avoiding the following five actions: Eating or drinking, wearing leather shoes, applying lotions or creams, washing or bathing, and engaging in conjugal relations. Also remember that Yom Kippur has almost identical restrictions to Shabbat, including not carrying outside of an eruv or using fire in any way.
2. Feast Before You Fast
It’s a mitzvah to fast on Yom Kippur, but it’s also a mitzvah to feast the day before. Even if you will not be going to synagogue, you should still enjoy the traditional two meals the afternoon before the fast begins.
3. Call Family Members
It is customary to wish family members and friends a gemar chatimah tovah - may G‑d seal us in for a good year. When so many are in isolation, this takes on added significance. Think about who you know that could use a pre-holiday pickup, including those outside your immediate circle, and pick up the phone.
It is also customary for parents to bless their children before the onset of the holiday. This may be done over the phone or via the video-conferencing app of your choice.
4. Dress Up
Even though you will not be at the synagogue, you should still dress up for Yom Kippur services. Ladies: Be sure to wear as nice a skirt or dress as you would wear any other year. Gentlemen: If you wear a white kittel every year, do so this year as well. Same goes for your nice suit and (of course) your tallit.
5. Light Candles
Yom Kippur is a holiday, and it is ushered in by lighting candles (married women light at least two, and single girls light one). If you are sheltering in place in a male-only household, one of the guys should light candles for everyone.
6. Prepare to Be Your Own Cantor
Most of the lengthy additions to the prayer services are found in the chazzan’s repetition to the Amidah (silent prayer), which is not said when praying alone.
The best way to get yourself up to snuff for praying at home is to have a Yom Kippur machzor (prayer book) handy, and simply follow the instructions, omitting the parts that cannot be done alone—principally the Barechu call to prayer, Kaddish, the Repetition of the Amidah, and the Torah-reading service.
Prepare additional material relevant to Yom Kippur in advance so that you can read it during free time.
7. Don’t Forget the Kids
Even though they may not be fasting, don’t forget that it’s also Yom Kippur for your kids, and they need to have a meaningful, age-appropriate experience. Added bonus: the more engaged they are, the easier your day will be. Try to prepare activities and snacks in advance, including purchasing a special book or two, to be taken out only on Yom Kippur. Having pre-prepared snacks and meals in the fridge will make things much easier for you when the migraines set in and smearing peanut butter and jelly seems like a daunting task.
Yom Kippur is one of four times each year Ashkenazim recite the Yizkor memorial prayer for our dear departed ones in the synagogue. The primary element of Yizkor is the tzedakah we pledge in merit of our loved ones—something you can do anywhere in the world. If need be, you can recite Yizkor privately at home, secure in the fact that this is what G‑d wants from us right now, taking comfort in knowing that our loved ones would surely want us to stay safe.
9. Break Your Fast After You Would Have Heard Shofar
The final part of the Yom Kippur synagogue services includes the blowing of the shofar, which is timed to coincide with the moment that night has fallen and the fast has ended. If you will be at home and unable to hear shofar, make havdalah and break your fast after night has fallen in your area.
10. The Main Thing
Don't stand for hours in the sun if this will cause you to break your fast early. Do not fast if it puts your health at risk. Focus on the main thing. Despite the fact that this Yom Kippur is different, its essence does not change, no matter where we are: "For on this day He shall effect atonement for you to cleanse you. Before the Lord, you shall be cleansed from all your sins."
May all news be good news, and may everyone be inscribed in the Book of Life.