I'd say that the best routine for scales and arpeggios is not to have a routine. I found that having a routine turned off my brain and stopped progress. So now I get my teacher to suggest different aspects of scales or arpeggios to work on, speed, evenness, tone, connection, feeling the weight, hand coordination, what have you, and then do 10 minutes of them focusing on whatever it is I'm interested in. And change the focus from week to week if not every few days. I think that is more useful than saying, OK, every day I'll do either all the major scales or all the harmonic minor scales in (pick octaves, thirds, sixths) and then set up a regular rotation. The more routine a routine becomes, the easier it is to let your mind wander.
Topic: Daily practice routine for amateur advanced pianist