What should be the daily routine of an UPSC aspirant?

Newspaper (The Hindu or The Indian Express) - 2 hours + 30 mins (notes making). If you are beginner could take more time.
NCERT - 2–3 hours.
Optional - 2 hrs.
Answer writing + prelims daily questions - 1 hour (after finishing NCERT).
Thinking on current issues happening.
Follow your hobby.
Revision on weekend.
Go to bed with satisfaction that you learnt something today for gaining knowledge. Not for marks. But don't be overconfident. Be cautiously optimistic.
This would be enough. After few months, increase your study hours and intensity gradually. This will help you sail in this UPSC journey.

Good luck :-)