Try these in D:

For a transition from D to Bm in 4/4:

Alternate open D/strum/open A/strum/open D/strum then
Open E/hammer onto F# (use your thumb if you can)/open A/B/strum Bm
The E & F# are 16th notes; the A is an 8th note

-If the song opens with a Bm, you can use this for an intro, starting at the open E


For a change from A7 to D (all 16th notes):
open A /B/C/C#/D chord.

For a flashy ending to a solo, You can start that on the low E string, again all 16ths:

E/F#/G/G#/open A/B/C/C#/D (double the note at the end by playing the D on 5th fret of the A string, and the open D string, on the same pickstroke.)

Have fun.
W-O