Select any note in the scale to act as your chords root note. Now continue up the scale selecting every other note until the root note repeats itself. In the example below we can see how this would work.
Each note selected is named after it’s interval distance from the root note of the chord.
Notes chosen past the octave are also named after their distance from the original root note, so a Second becomes a Ninth, a Fourth becomes an Eleventh and a Sixth becomes a Thirteenth. These notes are called Tensions and they are used to add flavor to a chords sound.
The first three notes (root thru fifth) make up the meat and potatoes of our chord. They are called the Triad.