Miesha needs to pick her strikes. She doesn't set them up enough and with Rousey's newly displayed punching power, not setting them up will get her killed. Lots of jabs, circling and combos timed for maximum impact.
Miesha should also accept that she's never going to win the scrambles. Rousey is the best in MMA when it comes to standing to ground transitions. World class Judoka are masters at adjusting in mid throw/flight. The best she can hope for is to take minimal damage when she lands and either try to gain guard or escape to stand.
Miesha has a small chance of winning and it relies on either knocking Rousey out with a TKO or tagging Rousey hard enough that she can capitalize with a submission. GnP is a BAD idea as it's unlikely that Miesha will end up on top with a take down even if Rousey is stunned. Rousey's instincts will just kick in and Miesha will end up on her back. If Miesha stuns Rousey, she should either keep striking, or look immediately to take her back, or possibly to get a standing submission. In other words, RNC/kimura/guillotine.