Add the lemon juice and honey and stir together until the honey is broken down and blended. Personally I like a little more whiskey and a tad less lemon juice.
Then add a few pieces of ice and top with tonic water.
Garnish with a mint sprig and lemon wheel if you've got'em (in this quarantine time I don't...).
Notes
You can use either fresh or bottled lemon juice for this, but I personally strongly prefer it with fresh