[*Easter Egg Humoresque Ending at the end of this video*]
When practicing shifts, you don’t always get to shift to notes on the same string but you should follow the simple rule ‘Old Finger to New Position’. The last finger you play before the shift is the finger that shifts into the new position. Like everything in violin, there might be exceptions, but rules are rules!
I use Suzuki Book III, Humoresque as an example:
To simplify shifting (and any technique) to a basic exercise, reduce to do it all on one string.
Eliminate arrival note.
Create a shifting exercise which adds the actual shift between the notes, gradually reducing the duration of the shift note until it can no longer be heard. Practice it forwards and backwards.