I like to use Light Mode during the day and Dark Mode when it gets closer to bedtime. I know it sounds lazy, but when you use Obsidian at all times of day every day, it can be kind of inconvenient to have to go into your settings and manually switch to Light or Dark mode twice a day.
I think it would be useful to be able to tell Obsidian to be in Light mode during a certain time frame, and in Dark mode during the rest of the time.
E.g. Light mode: 8:00 AM - 9:00 PM | Dark mode: 9:00 PM - 8:00 AM
That way it switches automatically depending on the time of day without you having to think about it or go to the trouble of switching. The setting would be under Appearance>Base Theme, along with the Light/Dark mode setting itself.
Manually switching between Light mode and Dark mode using the settings menu
This feature request for a Dark/Light mode toggle hotkey would be another potential solution, although each idea would work better for different people with different preferences.