Any tips on how to approach this in an efficient manner? :)
How to best prepare for GMAT?
Having taken the GMAT, the approach really depends person by person, depending on your skills. The general advice of taking a prep "diagnostic" test first is good advice - you can find an official one on the GMAT website. Based on how you do, you should plan your prep accordingly. Personally, I found the Sentence Correction questions the most challenging, and found the Manhattan prep book on Sentence correction a super useful resource.
Note, however, this isn't the best forum for GMAT-specific questions. Check out Gmat club for the most extensive discussions of prep strategies, resources, and detailed solutions to pretty much every question out there.
Let's assume you have neve evenr looked at the GMAT, are time constrained and don't expect to get a maximum score -
1. Take a sample test, to see where you struggle (comparatively)
2. Get a GMAT Prep book and study these sections specifically
3. Take a new sample test once or twice during the prep time, to confirm you are on the right track and focus on the new 'worst sections'
If you have more money & time available, you can always buy a prep course; I would not recommend it, the GMAT isn't all that important in the grand scheme of things.
PS: Don't forget to look at the GRE, since many MBAs now accept it.One of my teammates is preparing the GRE currently since he did better (again, comparatively) on the GRE vs. GMAT. Why study something you are worse at if both are acceptable?