“I just took my time in front of the mirror.”
Take one's time means to do something slowly without rushing; see A2-04. Frank means that he simply spent time carefully working in front of the mirror.
A2-10 / CEFR A2 / EPISODE 10
Complimenting a new haircut
SceneTina notices Frank's new haircut.

WORDS & CONTEXT
Take one's time means to do something slowly without rushing; see A2-04. Frank means that he simply spent time carefully working in front of the mirror.
Here turn out means to end up a certain way. Even after hearing that Frank's hands were shaking, Tina praises how well the haircut came out and asks him to cut her hair.
In haircuts, a little off ... means cutting a small amount from something. It is like saying I'll cut just a little off the bangs.: Frank agrees, but limits how much he will cut. Bangs is American English for the hair over the forehead (British English says fringe). This is a different use from the radiator that bangs (makes loud noises) in A2-23.