Snap! There it is, that moment every angler knows, and maybe the most frustrating part of the whole sport.
After spending some time, perhaps quite a bit of time if the flies are small and the air is cold, tying on your weapon of choice, your tippet snaps. It's a moment of grievance followed by profanity followed by frantically checking to see if you've fumbled the knot or if the tippet's gone bad.
You know it's worth it to double check everything and it's better to break off standing by the car than in a 20-inch rainbow's mouth, but there are currently no clear, rational thoughts in your head. It becomes worse when you've lost your size 24 midge in the parking lot.
I find myself in this particular predicament often, mostly in the winter.

Step-one in the process is to softly whisper "damn" under your breath, anything louder or more vulgar and you will appear mad.

Step-two is to cut off the tippet. It's now completely useless and your only option is to throw it away. After all, your measurements were perfect before the break, now it's all wrong.

Step-three, test your spool of tippet if it's bad. You may as well pull it off your pack or lanyard so you don't make the mistake of using it and breaking off on your dream brown.

Step-four, if you aren't sure if it's bad or not (6x to 8x can be tricky) just say it is bad and bum some of your fishing partners.

Step-five: go fishing, and if you lose a fish, it was most likely that bad tippet you've got.