The traditional approach to transits is to divide them into two categories: good transits and bad transits. The so-called good transits are the trines, the sextiles and half of the conjunctions and they make everything go smooth towards success, while the so-called bad transits are the oppositions, the squares and the rest of the conjunctions, and they represent twists of malevolent fate.
However, it is not always so.
The "bad", difficult transits by touching sensitive points in your life or your own character may help you gain strength and experience or just help get yourself together in order to achieve higher goals. Also, during the difficult transits one might experience a purifying process in the respective area of life, although this is not always immediately obvious.
In the meantime, the "good" easy transits may reinforce your weak points by not providing any stimulus of growth, any guidance regarding the right thing to do or the right direction in life. As a result, under selected circumstances, some of these transits may do even more damage than the so-called difficult ones, although this is not apparent until the next difficult transit of those two planets.
In either case, a spiritual approach to life is recommended in order to live all transits as opportunities of spiritual development, regardless the level of material or emotional gain or loss, comfort or distress.
(article based on ideas presented in Robert Hand's book - Planets in Transit, a must read for any person approaching the study of astrology)