The following is a drill Van used to teach us in the torture chamber, I'm sure he's still doing it and it may have evolved, but this is how I do it now.
It begins with a right hand attack, stepping in with your right and lowering your balance begin with the Kanshiwa bunkai style horizontal strike, after the block. Then bringing your arm down along the top of your opponents arm strike with the rear of the elbow, near the tricep, while pulling his arm with your left hand. This multiplies the power of the strike.
Then step across his right foot with your right foot transferring the grip of his arm from your left to your right, turn your hip while simultaneously doing a rear elbow strike with your left. Then transfer the grip back to your left hand and ride the opponents right arm with your elbow striking to the side of his head.
There are opportunities for knee strikes and foot stomps in all this.
A great inward fighting drill.
What I can't emphasize enough is the hip movement, and the "kazushi" or pulling off balance at key points to intensify the strikes.