An ADJECTIVE is a word that describes a person, place, or thing, giving us more information about it.

Adjectives that end in -ing describe a characteristic of that person, place, thing, or situation that CAUSES a feeling/emotion. 

-ING adjectives = CAUSE an emotion

Adjectives that end in -ed describe a state of being or the emotion that one feels.
–ED adjectives = RESULT in an emotion

Many times these adjectives are derived from nouns and verbs e.g., to stun > stunning, stunned; to tire > tiring, tired; to bore >  boring, bored: to disgust > disgusting, disgusted, etc.

Examples:

The long car trip every weekend is very tiring for me. (It is an experience that CAUSES me to have an emotion.)

I am tired from the long car trip every weekend. (I feel tired. Tired = lacking in energy. Tired is the EMOTION I have after I drive for a long time.)

Pineapple on pizza is a disgusting thing to eat. (It CAUSES an emotion)
If you serve me pineapple on pizza, I will feel disgusted. (It results in an EMOTION)