Self introspection is a brave act in my point of view. It demands lot of courage.
Now to do self introspect, Timing is most important. Just before going to bed is the best time to do so. Note down you whole day activity and practice this for 21 days, as it is well know it become your habit. Carry this for 2-3 months honestly, you will definitely able to find out you strength and weakness.
PS: You will have to be very blunt and brave to accept your weakness.