Hello I'm fairly new to these forums and still getting used to the feel.

To start off, this is my suggestions for your perfect practice session and general warmup. I always suggest warming up off stage before any performance. 

Beginners:

i classify beginners as those who work only in 1st position. You use very little bow technique, dynamics, and little to no vibrato.

warmup 1: Moto perpetual. Yes yes I know. Advanced piece. For beginners I suggest that you go at whatever pace you can quickly hit the notes in the first few measures.

warmup 2: Scales. For beginner do a one octave D Minor, 1 octave D Major, 2 octave G Major, 1 octave C Major.

warmup 3: bow technique. Pick a scale, and do it whilst ensuring your bow is not over the fingerboard.

Intermediary players:

i classify intermediate players as those who can play in 1st, 3rd, and 5th positions, high level bow technique (you can do techniques such as spiccato and martele). You can vibrato.

warmup 1: Moto Perpetual. Go up to the first repeat and stop. Try to do the spiccato if you can. 

Warmup 2: do various scales with vibrato. Do allegro with vibrato in every note, and do andante with slow vibrato. 

Warmup 3: play a beginner piece, but break off and improvise.

advanced:

i classify advanced players as those who are not limited by shifting, vibrato variously, accentuate dynamics, and play well in tune.

warmup 1: Moto Perpetual with LOTS of expression

warmup 2: G Minor 3 octave G string, D Minor 3 octave D string, A major 3 octave A string, E major 3 octave E string. This requires very heavy shifting but yields great results.

warmup 3: 5 octave G melodic minor scale with full bows, vibrato, and expression 

Professional:

i consider a professional someone who is mastered in the majority of techniques.

warmup 1: repeat warmup 3 from advanced 

warmup 2: begin improvising 

warmup 3: artifical harmonic excercises

Warmup 4: write a cadenza for beginner pieces. Stay true to the original chords and work. Be creative. (Suggested for soloists)

I'll be glad to answer any and all questions