How does one prevent boxers from riding up? This occurs even when I wear a belt and tuck my boxers firmly under the pants.
Well, whatever you do, don’t tuck your shirt into them - that virtually guarantees boxers über pants.
I don’t have this problem with my regular everyday pants, which are slacks or chinos. I used to have the problem with jeans, but fixed it by just not wearing underwear with jeans.
It’s been a huge pleasure to watch you progress from deep philosophical OPs to more practical matters 
I have no idea. I flirted with boxers for a short time in high school. It was uncomfortable and felt like I was wearing shorts under my pants all the time. I moved to boxer briefs and then to briefs and I haven’t looked back since. (I keep a few pairs of goofy boxers for their comedic use, but that’s it.)
Boxers really only work with very smooth fabric that isn’t too tight (like chinos). They don’t work with today’s slimmer jean styles just because of the inevitable friction where the fabrics meet. Try boxer briefs if regular briefs are just too dorky for words.
I don’t understand why anyone would wear boxers under pants. They are always going to ride up and they offer no support. I would try boxer briefs instead and you won’t have this problem.
knee socks and garter straps.
Reach your hand inside your pant leg and pull the legs of the boxer down far enough that the waistband starts to “tug” downward. Then when tucking in your shirt, make sure you don’t ruin the boxers’ neatness.
That should hold you for a bit. It’s all about how you tuck things. High boxer legs = eventual high boxer waistband.
I wear boxers every day. Under jeans, under chinos, under dress slacks, under shorts. I never have a problem with them riding up. I’m not sure what I’m doing differently from a bunch of other people…I just take a few second after I pull my pants up to push the legs of my boxers back down so they are laying flat like they should be, and they stay in place.
I tried boxers my first week of basic training. I hated them because they rode up, and after a short run their waistband was around my bottom ribs and they were crawling up my ass.
I switched back to briefs and had no more underwear problems.
I wear thin Fruit-of-the-Loom boxers, they are no problem. I have some boxers with thicker material that are less comfortable with tighter pants, but most of my pants aren’t at all tight.
Get a beer belly. That way they always ride down. Works for me.
Update: This problem appears to have been solved via belt tightening even when wearing jeans.
You could send them to puppy school to learn to behave better?
Stop shopping at Grace Bros. 