I originally used Ketostix but wondered why I always got very low results until I discovered i was just seeing
waste ketones in my wee. After a bit of research I bought one of the original Ketonix breathalyser gadgets, which records ketone levels via acetone on breath, and uses a traffic lights system to show these. It was a highish one-off cost but I've had it now for over seven years. It 's somewhat less accurate though than blood ketone meters, but more accurate than the urine strips, and its main benefits are that I can use it as often as I choose for no extra costs. Later versions are much more sophisticated now AND much more expensive.
I've also used my Libre reader which as well as scanning the sensors will act as a meter and takes both blood and ketone strips.
And
@Camoo, while husband is a dedicated carboholic,
I've seen a number of health benefits from eating a low carb/ketogenic type diet - so I've not only improved my glucose levels, but no longer suffer from life long chronic migraines, and especially important to me as my mother suffered from senile dementia, is that
my elderly brain runs much more happily and clearly on "keto power".