What's the best way to mount one of these things on a circuit board or in an enclosure?

Miniature tuning capacitor

A lot of these things have threaded holes, but this doesn't. Only way I can think of is to hot glue or superglue it...but it seems a bit permanent and drastic.

Is there a trick?,

 

Not real sure but, isn't that the job of the small round pins on the bottom? If they arent a part of the electrical connections a separate isolated pad will be needed in the board layout, for each pin.then the pin is soldered to that pad.

 

Many ways can do, but it depends on what you trying to do.

Here is the one:
How to make a AM Radio from a box.

 

Those four pins, haven't they 0,2 of an inch separation? If so, you could consider asembling it as common components.

Just for you to know a possible way, where your imagination plays an important role, google for "ugly style" and "Manhattan style" what is common practice for amateurs into RF. Essentially you solder everything.

Some months ago I assembled a wideband amplifier using kind of Manhattan style and worked on then first try. The nice part of it that could start laying things on the board mimicking the schematic, provided it's reasonably drawn.

Planning things on paper, more or less to scale, does help a lot. Be brave and go. Just a word of caution: when placing the "islands" with super glue, keep in mind that setting is too fast. No changes of mind at the last moment. Been there, done that...

/edit
Rereading what shortbus posted, it is essentially what I am trying to say. Sorry.
/edit

 

For AM it is not that much critical.

Actually you can solder such components to proto PCBs.
Just use them upside down.

You can still mount some components on the other side.

Otherwise, you can also drill holes easily into cheap proto PCBs without a drill. Screwdriver or a cutter knife.

For epoxy PCBs, you need a real electric drill.

If you want to use an enclosure, the PCB needs to match. You can also use a small carrier PCB for that component. It's not a problem for AM frequency.