Rhythm is Everywhere. Use it!
Many intermediate guitarist have trained to reach good skills in many important areas of their guitar playing. But one skill that is often neglected is the art of transcribing rhythm. If you want to immediately improve your ability to express yourself on the guitar read on and try what I suggest.
When training for example on a scale most guitarists use an even rhythm. That is reasonable since the skill in training should be usable equally fast at every time. When you then go on and try to improvise something you should concentrate on getting out of the even rhythm. To make that simple I will present several ideas on getting an arsenal of rhythms.
Technique 1: Listen to your favourite music.
Did you ever listen to your favourite music with a special emphasis on rhythm? I encourage you to do this. Hum with the melody or tap your finger in the rhythm and you will notice how rich the music is. Make an attempt to write the rhythm down. If you are already versed in music notation this will probably not challenge you, but nonetheless this is good training for your rhythmic skills. If you do not (yet) know music notation you could use length of lines as an indicator of note length.
Technique 2: Listen to people speak.
People are able to speak in a monotone rhythm, but usually they don‘t. You could try to get rhythmic ideas from the rhythmic patterns people use to phrase their words and sentences. Try to note the ideas down again; but more importantly: Try it with your guitar! The easiest plan would be to just play an open string and pick the rhythm you have just identified. Once you got that you could play little melodies with the rhythm.
Identifying the rhythm in speech patterns might be easier to do with a recording in a language you don‘t speak so that you are not as much focused on the meaning of the words. Most DVDs have tracks in other languages.
Technique 3: Listen to your surroundings.
Many aspects of your environment make sounds in rhythmic patterns. Listen to them. Examples are singing birds, a printer, people climbing stairs, the clock on the wall, the typing of your colleague, the wind in the leaves. Especially the combination of several of those can get very interesting.
As you just read all of the techniques presented focused on listening consciously. You can apply this everywhere and anytime. Use the ideas you have collected in a jam session or when improvising with a backing track and see whether you can make them sound good.
If you find an especially nice rhythm I’d be happy if you contacted me, Rene Kerkdyk, at Rock Gitarre Hildesheim. There I teach student how to use ideas like this to express themselves with the guitar.