I always practice 1 hour scales and arpegio's. (Thrids, 4ths, 5ths, 6ths, everything I can think of)
1 hour on a piece or even section of a piece with a difficulty in, for example today I did the 1st 2 paganini variations by Brahms tokeep my 6ths nice and heathly. Or a Chopin etude, or anything etude like.
Break
Then 1 hour per piece. With breaks between each hour. At the end of the day revise what you have done very briefly. If you have a big piece to learn like a concerto, spend longer on it. As the piece develops, you'll start spending less time on it, and when that happens, just start memorising, and memorising seperate hands and stuff like that.
To practice effieciently just stay focused. Make things fun, spice it up. Make the pieces harder, look deeper into the music. If you get bored, leave for 5 minutes, and just have a cup of tea.