Agree with other posters that once you've adjusted from the pre-dx high levels, hypo response will more likely kick in below 4.
Like the shakes people get after a "fight or flight" panic, the shakes are caused by an adrenalin rush which is aimed at getting your liver to release glucose so as to fix the low sugar. So although they undeniably feel lousy, it's your body trying to fix itself before it gets any worse.
As time goes by, you'll probably learn to pick up on much subtler things which'll warn you before shaking, for example, some of us feel a sort if lightness, and that'll give a heads up to go test before things get too extreme.
When I was newly dx'd I made some pretty dumb mistakes like thinking, it's OK I've got some biscuits in the kitchen. Turned out that managing to get from the bedroom to kitchen to get the biscuits after waking hypo at 2am is about as easy as crossing the Alps in flippers, so learned pretty soon to keep stuff right beside the bed.
Another mistake was to overtreat. I used to just stuff myself with a Twix and keep on eating till the symptoms went away. Wrong, why? Twix has fat, slows down absorption, even neat lucozade will take a while to show up in blood, and it turns out 10 to 15 grms will sort out most minor hypos anway. So now I'm more like 10 grms jelly beans or 50 mls lucozade then wait 10 mins, test and repeat if not sorted. Sure, there'll be messier hypos where those rules go out the window, but for most, just waiting that ten minutes to give the chance for it to actually show up in test avoids overtreating and ending up at over 10.