Lagrima should be played with a lot of feeling. It is of moderate difficulty, but should be very attainable if one pays close attention to the fingerings of the left hand. The repeated open B should be subdued, allowing the beautiful melody to ring through. On the repeats try to change the dynamics a little. Rolling the double stops, (two note chords), here and there, will add character as well.
I found these 2 videos from Youtube, explaining both Right hand and Left hand technique for Lagrima.
Part 1: The Right Hand Technique
Part 2: The Left Hand Technique
Score can be downloaded here: