Twiddle twop's

These are refered to your fingers or digits, but only when your twittering.

You could use twiddle twop's or twiddle twip's.

twips, may sound like whips. Fingers are like little whips when they are twittering.
twop's is created from two, as two digits are usually used in twittering.

Twiddle may eventually be the many variations of twitter, be it past tense, verb or something else.