I've owned the same pair of Danner Mountain Light II's since 2012 and have never had them resoled or serviced. These boots have been with me to 15+ countries including trekking in India, have been on many, many hikes and all I do is clean and polish them every few months. I estimate I have walked at least 2000km in them, never had any issues. Can't recommend Danner enough.

Personally, I've found that polishing my boots is a really enjoyable task, it's quite cathartic to sit there for a few minutes with dubbin and a brush and clean your boots up.

It's funny, because I used to hate polishing my school shoes as a kid.

I only polish my boots around once a month, so it's a couple of hours a year. I spend more time sewing up clothes and sewing on replacement buttons, which I've also discovered now that I'm an adult is a cathartic activity.

There's something nice about trying to distance yourself from the throwaway disposable consumer culture we have now, and actually fixing things.

I guess I've become a hipster.

Use a horsehair brush to get whatever chunks of crap off - I pick up a lot of mud, maybe you do too. Remove any remaining dirt or dust with a wet rag, maybe a little saddle soap if they're really filthy.

Wipe off any lingering water, let the leather dry, and then apply a thin layer of mink oil - work it into the creases, that's where the leather will split if you don't keep it supple.

Let that dry, and then apply a very thin layer of polish with a damp - not wet - rag. Work it into the seams; if it's not under your fingernails, you're not trying hard enough. Once the entire upper is done, give it a few minutes to sit, so the wax can solidify a bit, then buff it lightly with long strokes of the rag. Repeat with another thin layer of polish.

You won't get much of a shine the first time. The temptation is to apply polish more heavily, but then it just gets sticky. Next time, you can buff it more firmly, and next time more firmly still. After a few goes, you'll have enough of a layer built up to develop a proper shine, and then it's just a few minutes of maintenance at a time. You'll never get a really good gleam off anything but black leather, but anything else will still look much better than if you don't put the effort in. Same for any leather that's not full-grain, but it still helps. And don't polish suede! Just brush it.

Mink oil every half-dozen times or so is enough to keep cracks from forming; more often than that and it'll soften the leather too much.

I get ten or more years out of a good pair of boots this way. Dress shoes are more delicate, I suppose, but they'll still do better with proper care than without. Good luck!