I'm not a guitarist, so I was going to ignore this question. However, as a keyboard player, I noticed that I use a lot of very similar inflections. You should get a proper answer from a guitarist (or twelve) shortly, but I thought it could be worth throwing in my two cents.
Chordally speaking, the two patterns you mention are D
Dsus4
D
Dsus2
D
and A
Asus4
A
Asus2
A
[see note]. It's a pretty simple idea, but effective.
Here's some similar ideas. Some are more inventive that others. I've used chord
to represent the non-extended chord. Also, the inflection may end on the next chord in the progression, if the pattern allows it.
sus4
-> chord
or sus2
-> chord
. Pretty obvious, but it's the basis for most of these ideas.
sus2
-> chord
-> sus2
-> chord
. In D, one of the strings would move E -> F# -> E -> D.
chord
-> 6
-> chord
-> sus4
-> chord
. This is a similar idea, but you move the fifth, not the third. In D, one of the string would move A -> B -> A -> G -> A. This might require a different voicing of the chord; I don't know enough to help you here.
These ideas are genre dependent, and can sound really out of place, or annoying if overused. I tend to use them as a light seasoning, to add some interest.
I also use patterns involving major sevens a lot, but I don't know if that will translate well to guitar. Experimentation is recommended.
I would also play around with the IVsus4
chord. In D, that's Gsus4. The suspended 4 is a C natural, not the C# that's in the key signature (think B-> C -> D -> C -> B). It has an interesting sound. You can also try playing around with the #4 (i.e. B -> C# -> D -> C# -> D). It's much more dissonant, but can be musically useful.
I hope that starts you off. If not, there's a bunch of good guitar types around here who should be able to correct me, and point you in the right direction.
[Note] Technically they might be add11
and add9
chords, if there is a third on one of the other strings, but I would consider that distinction to be academic for this purpose.