Here’s the thing about jeans: they’re jeans. You may have been told this before. And jeans, being jeans, look best after you beat the crap out of them. Yes, I know you want to wear “dressy jeans” with an odd jacket. Let go of this mid-aughts conception (and abandon the club-ready striped shirt, too). Even worn with an odd jacket, blue jeans aren’t dressy. That’s okay, though - if your jacket is of casual length and construction, and the jeans have lost the sheen of new denim. Accept that they won’t stay that crisp, beautiful indigo forever; learn to wabi the sabi and your mind (and your jeans) will thank you.
Getting to that state (mental and physical) takes dedication.
Walking the dogs? Denim time. Gardening? Denim time. Changing your oil? Yup (for those who live on the US East Coast: there are these things called cars. They have engines, the operation of which is aided by a lubricating oil, which must be changed every so often). Cook in them, dance in them, hike in them, forget your worries about stains and wrinkles and creases. Once you’ve worn your jeans into a pale, chalky blue, that oil stain is going to be just another mark of character (again, for the US East Coasters: you could substitute an olive or truffle oil stain).
Worries are for trousers, which jeans are not (denim trousers excluded - always exclude denim trousers). Don’t agonize over length. Let your jeans stack, or, if this bothers you, cuff them until they hang straight. If you hem them at all, wait until the denim settles; that way, those starchy folds have time to calm and crease. If you wear your jeans with a collared shirt, you’re not obligated to tuck it in. And please, never iron your jeans.
A lot of people still think jeans can only be worn with sneakers - sort of like how once upon a time people thought you couldn’t serve burgers in a fancy restaurant. Credit Hedi Slimane with encouraging people to wear derbies with their skinny jeans. But I’d suggest boots. If you’re wearing slubby Big Johns, try balancing out your cuff with a pair of heavy boots. If you’re wearing a slimmer cut, experiment with letting them stack atop a sleek pair of Buttero side-zips.
Despite everything that I’ve written above, there really are no rules for jeans. You just wear them.