CHORD PROGRESSIONS
EXPLORING TRIADS ON HARMONIC PROGRESSIONS
In a next step a harmonic progression is used to explore the triads. There are endless possibilities for useful harmonic progressions, the following is just a single example on how to start exploring.

More common triad chord progressions can be found here.
HARMONIZING SCALES
A scale can be harmonized as well, and according to many musicians throughout the 18th and 19th century this scale harmonization or 'octave rule' was used as a guidemap.
The following example is an 18th-century version in major and minor key. This harmonic progression was not entirely used in the exact order, but rather in fragments. It is therefore an ideal exercise to look for different combinations while playing.
the numbers below the chords indicate the current 'basso continuo' notation. Once this exercise is memorized it can be transposed to other keys.

Simultaneously with this exercise, an introduction to the musical functions such as tonic chord, dominant chord and subdominant chord, could be interesting.