What is the most important issue for the left hand is for it to be relaxed. There are different schools of thought of how the left hand should be. Some violinists play with the fingerboard resting on the web of the hand between the thumb and index finger. This is based on the Russian school of violin playing training and is shown in the example video below by violinist Egor Gzechishnikov. Others make sure there is no space between the violin and the left hand which is demonstrated by Yehudi Menuhin in the video below. He discusses this at 4:30 if you want to get directly to where he demonstrates the relationship of the left hand to the violin. In my video, filmed in the Rhodope Mountains of Bulgaria I discuss the very basics of bringing the left hand to the violin. So no matter where your contact point may be it is important to be relaxed and your palm is facing the fingerboard.
Thank you Heather, what a wonderful idea! I must say I that I am having a bit of difficulty with the "mouse hole" as I've been playing with the fingerboard resting on a cradle made by the the pad of the thumb and the lowest (biggest) knuckle of the index finger; consequently there is a hole, albeit for a small mouse:-). I love your choice of landscapes in your videos, many thanks for sharing that too. See you on YouTube!