1. Changing between major/minor scales gives your chords different moods. "Major scales are considered to convey a sense of brightness, excitement, happiness, whereas minor scales are generally regarded as conveying the opposite and a different sense of arousal."

2. Pay attention to the roman numerals of the chords in the progression (e.g. I, II, III). These denote the root note of the chord within the scale. Try the same set of roman numerals across different scales. For example, if you like the way a I–V–VI–IV chord progression sounds, it will likely sound good in a different key as well.

3. Try layering your chords. Layering is copying the same notes across different ocatves. This makes your progression sound fuller.

4.Try different types of chords. Play around with triads, sevenths, and ninth chords.

5. Try syncopation. Cut up notes to give your chord progression some rhythm.

6. Use chord inversions to make your progression sound smoother and better. After you drag the MIDI file into your DAW, take a look at the notes and see where the notes jump far in-between chords. Fix these my re-arranging chords to make the transitions smoother.

7. For a good intro to the music theory behind chord progressions, watch this YouTube video by Andrew Huang. It just takes 30 minutes and takes you through all of the basics.