Pre meal & 2 hours post meal for however many meals I eat on any one day, maybe also morning wake up/fasting tests.
On an LCHF diet I rarely snack as I don't either need the energy boost or feel the need to eat between meals, and as a diet controlled T2 I don't have to manage my glucose levels with insulin anyway so for me there's not real need to test then.
Occasionally at other times and for other reasons, e.g. to check for faster or slower rise afrer meals, or for possible reaction to (new) medication, stress, I'll do extra tesing. It depends on what I'm trying to discover.
So possibly on average 6-7 checks.
Robbity