When you’re back on the Normandy, chat to Traynor for a new N7 mission: N7: Fuel Reactors. Also head into the crew deck and if James and Garrus are there, nipping in and out of the nearby rooms will allow you to eavesdrop in on an entertaining conversation. Also check your e-mails for a message from Miranda (if she didn’t die from an imported Mass Effect 2 save), she’ll request a meeting in person again on the Citadel.
Speaking to the Doctor in the med bay can earn you additional Reputation points, so too can speaking with Liara and siding with her over Joker. Now would also be a great time to buy upgraded versions of the guns your team will most likely use. Buy any improved modifications for them as well so your upcoming battles will be just that little bit easier. Finally, if you send an invite to Tali from your private cabin, you’ll unlock the new power Energy Drain (should you wish to apply and start upgrading this biotic power).