Happy New Year as well!
Re-taking the GMAT when you already have a 700 sends a message to the adcom that you don't understand the admissions process and/or you don't have your priorities straight. The fact that your 2nd score is lower or higher isn't the issue. Anyhow, what's past is past. Just leave the GMAT alone.
Beyond a certain threshhold (and 700 is basically that threshhold), it's basically irrelevant what your score is. It comes down to everything else - the quality of your work experience, the quality of your accomplishments (work or extracurriculars), and how well you convey your candidacy in the written application and interview.
As for what you can do in less than one year -- other than focusing on doing the best thing you can on your applications -- not much.
Real accomplishments are the result of cumulative years' worth of effort. You don't achieve notable things in a vacuum or expect them to materialize overnight. It takes time - more like years and years. You can't just "get leadership experience" because you one day decide you need it. You have to *earn* it. And earning those experiences and accomplishment, just like earning someone's trust, takes time.
In your case, continue doing what you're doing at you're doing at work, and focus on putting in your best effort on the written applications when you're ready to apply this summer.
Follow me on Facebook