If you're like many Americans, you've put off retirement planning for far too long, and the chickens are coming home to roost. The average 401k balance won't provide the type of income many are hoping for in their Golden Years. All too often, that leads folks to put their head in the sand and hope for the best.

But that's not our approach here at The Motley Fool. Our aim is the help the world invest better. And when it comes to retirement savings, there's good news: there lots of ways to improve your retirement savings via your 401k.

In the slideshow below, Fool analyst Brian Stoffel outlines 5 smart 401k moves you can make in 2015—starting with the most basic, and ending with a megabackdoor trick that could help you sock away tens of thousands in a tax advantaged accounts—every year.

Photos: American Advisors Group, Freemoneyday, Christian V, all via Flickr.