Answer:
Right side:
Meaning : A set of methods or resources
(Can't seem to find picture sorry D: )
Left side: Having a bag of tricks would look like a magician is constantly pull new tricks out of their (imaginary) bag.
Third panel:
Person 1: You always have a bag a tricks everywhere you go.
Person: 2: We all have one, some just don’t use it.
(The picture below is for left panel, just some ideas)