[Lizard]

I think it's fine, particularly for people who maintain a household, to have some single action lists -- the random stuff that just seems to come at you. There should still be some goal to these single action lists, some driving purpose. "Mow the lawn" might go in a household maintenance single-action list along with "Wash car". On the other hand, "Make plane reservations" sounds like part of a bigger project. Where are you making plane reservations to? Do you also need to make hotel reservations? Or pack? Maybe you need to confirm the dates with your significant other or whomever you're going to visit before you make the plane reservations.

Another approach might be to think about the goals that you have or the roles that you play. Maybe you could have a "Mom" folder (or name it after your kid) with a "school" single-action list (or maybe make each semester a project, so you can check off the whole project and have a sense of accomplishment) and a "medical" single-action list.
Meal-planning for the week (both pack lunches and sit-down family meals) could be a project with tasks for "plan meals", "buy groceries" and one for preparing each meal. This could be a project that repeats every week.

I also find that with non-work stuff, projects are less important than contexts. I don't think it will be a disaster if you just throw it all into one big "Life" single-action list but take the time to set up your contexts well. However, if you find yourself procrastinating on a task in a single-action list, you may want to ask yourself if that's because it's really part of a project and there's some other step that needs to be done first. For example "Repair light switch" has been sitting around glaring at me because I haven't bought the replacement light switch yet. Oh, but that's waiting until we decide if we're repainting the room, which... Sounds like I need a full "redecorate office" project. And maybe it'll turn out that I decide not to repaint and just need to go buy a switch. But at least I'll know what I need to do to get "repair light switch" from "to do" to "done".