How many kids and what ages? How old is the parent and what gender?
I usually take care of the parent first. Everything seems to be much easier when the parent isn't about to pass out, pee herself, and starve. I even lock her bedroom door so she can get a full sleep.
Don't worry about schedules or eating together. Make sure there's enough food and let the kids eat when they want.
Homework is cheap. Just buy another homework book if one of them gets lost.
Buy some wall defender lights and put them near the kids' beds if you're having trouble with monsters under the beds.
Get rid of the laundry stuff for now. That will save you a lot of time. Consider hiring a maid if you can afford it.
You can give the twins different clothes, hairstyles, and/or haircolors to help you tell them apart.