In this variation we need to make the melodic bass line sing clearly and, as always, look for the long lines in the phrases.
Practice the first note of every group of 3 and clearly show whether it is a 4-bar phrase (bars 1-4, 5-8) or a group of 2 bar phrases (bars 9-16). Make sure that the left-hand finger fall articulates clearly and rhythmically so that the bow can cross strings without hesitation. Settle the left hand by practicing double stops.
Try using a brush stroke (a slow sautillé stroke) and work towards a small, balanced string-cross action when crossing repeatedly within a pair of strings. When you need to change the pair of strings (for instance from bar 1 to bar 2 or bar 3 to bar 4), use a whole-arm string-crossing action to take the bow to a comfortable spot to pivot between the next pair of strings. Make sure that all the string crossings are as small and smooth as possible.
Practice the bow stroke on open strings and be sure to keep the up bows on beats 2 and 4 clear and articulated so that the rhythm and melodic line are clear. You can help the up-bow metric accent by initiating it with more bow speed at the beginning of the note.