Play 10ths!
In this article I talked about 6ths as an alternative to full chords, to open up your sound a bit. Sometimes even 6ths tend to sound a bit too close. If you are in a situation like that, try to play 10ths!
Tenths are really just 3rds, only an octave higher, so you get kind of a wider, "airy" sound. 10ths can imply all kinds of chords as well, depending on the musical context you play them in. 10ths can be major or minor, just like thirds. 10th is an imperfect consonant. You can sometimes hear examples of tenths played in popular music, jazz or folk, including African music.
Now let's check out how 10ths can be used on guitar and get used to the sound as well through the following example. Try to play the low strings with your thumb, and the high strings with your middle and ring fingers. Leaving the fingernails longer will help to get some volume on the higher notes:
If you would like to hear how the above example sounds like, you can do so by listening to the following sound file: major and minor tenths example, mp3
All you have to do is fret those simple shapes to be able to play tenths on your guitar's fingerboard. 10ths come very useful in all kinds of music when you are in need of spacious but subtle sound.