A riff is a short pattern of notes (usually one or two bars long) which repeats throughout a verse or section of a song. A riff can also be varied to fit a chord progression. Riffs are common in many styles of music including Rock, Metal, Blues, Jazz and Funk. Many of the examples you have already learnt are riffs. Here are some examples.
Riffs may be made up of single notes, chords, or a combination of both, as shown in this example.
Here are some more riffs. Learn them and then make up some of your own based on the ideas presented here. Don’t worry about the notes too much; just experiment until you find something that sounds good and then memorize it.
The following 12 bar Blues contains a riff which is altered to fit each new chord as it occurs. As with previous examples, play it slowly at first and gradually increase the tempo.
Here is a rhythm part which makes use of power chords, major chords and double note runs. Although this example is in the key of A, it is not strictly in a major or minor key, but makes use of elements of both. This is common in Rock. Whatever sounds good is ultimately the best thing to play, regardless of what scale, chord or key it comes from. Experiment with all the sounds you have learnt and have fun with them.