Great fun can be had with the sliding E shape, either with rasgueados as in the Grade 1 Trinity exam piece, A Fistful of Pesos by Nick Powlesland. Alternatively they can be used as a vehicle for making right hand arpeggio exercises more musical, as in Charles Ramirez technical exercises. Here is a useful graphic I have drawn of two sliding E shapes:
Play the blue notes first, followed by the orange notes.... Bicolour notes are open strings that belong to both! The blue chord is Fmaj7add#4/E for those interested. F something for those less academic! The orange chord is a simple E!
Today's little bit of randomness is thanks to a request from Jamie for flat 5 chords.... these 2 beauties require jazz fingering, they are completely moveable PROVIDED YOU MUTE OPEN STRINGS PROPERLY... If in doubt ask a teacher! Chord VII in the major scale is a Minor Seventh with a Flatted 5th (m7b5) or half diminished chord....
The first of these is a dominant 9th, sometimes called (incorrectly) a minor ninth. This chord is very commonly used in funk strumming. (Ask me and I will show you how!)
The second chord is a little bit nasty - this IS a minor ninth in full 5 string voicing. Probably better to play the four string version though and leave the root to the bass player, but it had to be shown so you could compare the "slang" minor ninth with the real deal!