That’s a simple rule I apply to everything.
What takes less than 2 minutes to do should be done straight away
This way you don’t add up to your todo list. Your brain is not getting full of small tasks as you do them as they come. So you don’t add up but stay efficient.
If it’s someone asking you something short, the fact of doing it straight away makes you look like an efficient worker. Saying “I will do it later I am busy” is not a good approach. Everyone is busy, and I don’t think anyone will think you are not busy if you help them straight away.
For instance, if someone ask you a file, grab it and send it immediately. Do not wait until you finish your current task. Yes, it’s disturbing your work process and focus. But if you do it now you are not being a blocker for your colleague, so you don’t stop his/her productivity and your reactivity and productivity will be much appreciated. Everyone would agree it’s so nice not having to wait.
Moreover, you have been disturbed from your current task already so you better kill this todo than push it for later (if it’s a 2 min task only). You also avoid chances to forget what people asked you and having them to ask again or remind you…