Ask HN: What are good options for selling or otherwise monetize unused domains?

I have collected dozens of domains in the years due to ideas or side projects that never materialized.

At this point I should really cut down on them, so I wonder what my options are to at least make some return on the sometimes years of fees.

I have no experience in this area at all and hope for some fresh ideas here :)

Some thoughts:

- Setup a 'for sale' page. I assume this only works for the more fancy names and eventually I have to find a way to make the payment and transfer happen without problems.

- Use a placeholder website like newsy.com. I am doing this for one domain and turns out I have only a few visitors per month. I hope that is not my most valuable domain ;)

- Use an auction marketplace domain. Seems rather useless and expensive for 'ordinary' domains?

- Just expire without having any return.

Any other ideas? Or comments on these options?