I've seen the words "frugal" and "cheap" used interchangeably on occasion, which is misleading. You can spend a lot of money and time dealing with problems if you always just pick up the cheapest thing, or take the quickest path. "Cheap" or "quick" can sometimes be efficient, but if you look far enough ahead, it's often not the case.
A little patience goes a long way toward maximizing resources. There are all kinds of examples. Almost anything you can buy in a store will go on sale at some point, if you keep an eye on it for a while rather than grabbing it right away. The latest technology gadget will cost a lot less after a few months. (Unless it's an Apple device.) Even watching TV benefits from waiting...let the DVR record it and skip the commercials.
Exactly what being frugal means to anyone has a lot to do with how much you value money and time. If time is most important to you, then you're probably willing to spend more in order to get something done faster. Likewise, if money is more important, you'll likely spend time going after bargains or making things for yourself. This balance is different for everyone, and it changes as your life situation evolves.
Another aspect of being frugal is being satisfied with what you have. There's always a newer, shinier thing out there: better cars, nicer house, bigger TV, faster computer. It's easy to get caught up in wanting the next thing, rather than sticking with what you already have as long as is reasonable. That's not to say that you can't have new things, but plan ahead and don't pick up something new just because it's shiny.
Being frugal isn't glamorous, and efficiency probably isn't going to make you famous. But on the whole, I find that I'm much happier when I know that I've made the most of my time and money.