With deployments coming down the pipeline, how can I best prepare my significant other for me being away? How can I prepare myself as an 2LT?

Don't make promises you cant keep like don't worry babe we will talk all the time or give any type of expectations like that. Even if you know for sure you will be able to, its best to prepare them for the worst.

I would add sir... Time does not freeze because your not there. Things will happen and you can not be there to fix it (if it needs fixing). Events will happen that you will miss. Hopefully someone took good pictures or videos. Memories will be made that you are not apart of. That is just part of what comes with the job. Last part, your other half will adjust to you not being there. So when you get back don't expect everything to be the exact same as when you left.
As for down range, look out for your soldiers. Try not to be the good idea fairy who sprinkles the magic dust then leaves once work start. Soldier take note on who's there just to get bullets points. Work with your NCO's. And know more than just the first and last name of your soldiers.
Best of luck and travel safe.

Don't get a general power of attorney, do specific power of attorney.