Look for Un-obvious Leaks
Or, in other words, give your cooling system a little extra loving.
Let's face it, if there's a puddle on the ground under your truck and you take a couple extra minutes to kneel on the ground, identify the color, and perhaps give it a sniff...you're really just doing the bare minimum. Not every leak is going to make itself known. If you pop the hood to give a friend a jump start or swap a burned-out headlight bulb, and notice the coolant tank level's chillin' below the MIN line, don't ignore it just because there wasn't a pool of fluid on the ground. Something's wrong. Yeah, it's normal for a little bit of fluid to boil away or evaporate -- but just a little. (And it's tricky, too, because it means a really small leak might not leave telltale stains, drips or wet spots.) Whenever you're under the hood, admiring that huge engine, take a moment to check the hoses and lines for wear or abrasion. Make sure all the clamps are holding snug. Replace anything that's worn out (which falls under "routine maintenance," which we'll discuss later). Refill the coolant to the proper level and check back frequently to ensure the level is staying consistent.
Maintaining the entire cooling system is crucial to keeping the engine at effective and safe running temperatures, and, sorry, but glancing on the ground for fluorescent puddles is really only a preliminary step that indicates, congratulations, you can identify a puddle. It's certainly good, but it's not quite enough. Truck owners should really make it a habit to poke around the engine bay every now and then. A leak too small to create a puddle can still cause massive engine damage if it's caught too late. Anything that allows the engine's operating temps to rise and stay above normal can cause damage...even a relatively minor breach in the cooling system.