When we try to multitask, we damage our brains in ways that negatively affect our well-being, mental performance, and productivity.
Bringing some simple mindful awareness to our everyday activities can help safeguard against this.
As far as is practical, try slowing down long enough to bring your full attention to the activity at hand. Single-tasking is a great way to support this intention. Bonus points if you can take a few mindful breaths while you're doing so.
Paradoxically, the more we slow down, the more efficiently we use our mental resources, freeing up even more time to accomplish more.