Little late to the party, but i'll list my current practice routine in the event that it's of any help. I like to practice in somewhat larger chunks (usually 2-3 hours) each day as opposed to short sessions. 

Scales - 30-45 min

I always focus on the scale with the corresponding key of the piece of music i'm learning. I've found starting this way really helps my intonation when I move on to the piece. I'll usually use a tuner for the first 1-2 times through the scale to help me hear the scale exactly in tune; then i practice the rest of the time without one to try and consistently hit the correct note. I'll set a comfortable pace for me (usually 40-60 bmp) and start with 1 whole note per bow, then two half notes per bow, etc. until i'm slurring 8 notes per bow while keeping the same bowing speed. I still only know 1st position; but i'd eventually like to incorporate 3rd position scales into this as well. 

Etudes/Specific Techniques - 30-45 min

After scales I work on etudes that cover similar technique to what i'll be playing in the piece like slurs, staccato, etc. The Wohlfahrt studies have been a huge help for that. I also have a few other books for specific technique. For example i'm currently learning how to play "Millionaire's Hoedown by Herman Clebanoff. A large portion of it has double stops; so during this time i practice double stops out of Harvey Whistler's "Developing double stops".

The actual piece - the rest of however long i feel like practicing.

Usually between 45 min to an hour and a half. I'll start by playing through the piece once or twice to see what sections i'm still having trouble with and then i work on those measures until i'm satisfied with how they sound. 

When i first started practicing i used to have no structure and would jump between playing the piece or scales or etudes basically at random. It was bad practice and since I've been paying more attention to how i structure it I've made a lot more improvement.