What do you do to refocus when interrupted during meditation?

I try to focus on my breathing to bring me back into that state. If that doesn't work, I imagine popping thought bubbles for each thought that distracts me.

For me, the best way is to deal with the distraction, to complete the action it might impose, and get back to meditation as if it was the most normal thing in the world. Mindfulness teaches us basically to not get wound up about things, and dealing with, 'closing' any interruption will allow you to put it behind you tranquilly.

Take a deep breath and notice where I feel it. Then notice where I feel the out breath then do a body scan to check no tension has crept in.

Just take another breath and focus on the air going in and out.

Although I have not yet practiced the skill of meditation, I like the practice to a focused work block. When distractions bide for my attention during such work sessions, I refocus by recognizing the distraction, deem it worthy or unworthy of my attention in the moment, and plan accordingly if it requires action immediately or at a scheduled time in the future.
I have been made aware that focusing on my breathing may also recenter myself, allowing me to continue with the task at hand and tackle my most important tasks.

Let the distraction go. Remind myself it's not a big deal. Restart whatever practice I was engaged in. Counting breaths, thought watching, focusing on a flower etc.
Distraction and interruption will happen it doesn't mean the session is "ruined". Don't look for excuses to give up.
Your mind will manufacture a ton of them when starting a new habit. Just start again, and again, and again.

This is what I do to refocus when interrupted during meditation. I take a deep breath in through my nose. Then breath out through my mouth while counting to six. For example, breath in one. Breath out two and so on until I reach six. This helps me to clear my mind from things that are distracting. As a result, I can focus again.

This may sound complex, but if/when I get distracted I think about the source it came from & ponder it's importance (if it's an urge, not a person).

Back to the breath, always reground myself on the feeling of my breath

Pause and take a moment. When I'm RE-relaxed and refocused, I can return to where I was. If this doesn't work, start afresh and try again!

I focus on my breathing and do a body scan to align myself more with my body

I normally breathe saying in my head "breathe in… breathe out" so I can refocus easier.