My idea (not very well developed) was to do it once 5 years after the amendment, once 10 years later, and once 20 years later.

The 5 year window would be for obviously bad amendments that really should never have passed. You just have to wait 5 years to try to fix things because that’s enough time for a set of elections to happen and power to change hands, so you don’t just have the same people voting on something.

10 years is for something that seemed like a good idea at the time, but a decade later has some obvious problems. Something like prohibition, or new amendments that might have been written in the wake of some major event like a terrorist attack.

20 years would be so the next generation has a chance to weigh in. Maybe older people were scared of the world changing to they wanted to enshrine something in the constitution to keep the world the way they liked it. Younger people would then have a chance to reverse it.

The idea is that there’s a 20 year trial period for new amendments. If they’re still thought to be a good idea, it should be pretty easy to rubber-stamp their renewal at the 5, 10 and 20 year marks. If the support for them has faded, they automatically get repealed when there aren’t enough people to support them.

I also just think it would be a good idea for amendments to be pretty common, even if all they’re doing is clarifying parts of the constitution that are vague. Like, whatever your position on the US 2nd amendment, you have to admit the wording is horribly vague. So, rather than supreme court justices trying to determine the historical context around those particular words, or people making weird analogies between railguns and muskets, you just open up the document, add a few clarifying words, and close it back up again.