Now that you have a piece of material trimmed and ready to drop into a box, what do you do? Some people just glue it to the bottom of the box (and yes, I have seen this done with what must have been a hot glue gun). This kind of thing is generally refered to as strictly bush-league.
We aren't going to teach you to do that here.

That being said, it should be pointed out on the other hand that it is possible to get so carried away with the mounts that the minerals themselves are lost sight of. I like to think of mounting as a means to an end, while still maintaining a high level of craft. There are those however that take extreme pains and for whom the crafting of mounts becomes an end in itself. There are no rules in this game. I will admire the patient craftsman, but am unlikely to mount many single crystals at the ends of cat whiskers myself. Nobody admires the slob.

First of all, we want all of our pieces to sit up at pretty much the same level in the box. In my case I bring them up as high as I can, so that if I sight across the top of the box, I can verify the piece is level, just below, or even slightly above the top (the lid does give a tiny bit of clearance). Doing this will require some kind of pedestal. The traditional choice will be corks of one size or another. I use balsa wood, because it is univerally available at any hobby shop or art store. Either way, the material needs to be shaped and then blackened.

Balsa or corks can be blackened in any number of ways. What I do is to use a giant black permanent marker and I find this entirely adequate. Another option is to spray paint the corks with a flat black paint (like Krylon ultra flat black). Some shake their corks in a jar with india ink. Touch up can be done with a permanent marker. Some object that the marker is not actually black, but a dark purple, but I have not found this to make a visible difference.

Above we have a before and after of an Arsenopyrite specimen from Zacatecas, Mexico (that is all the location that was given on the mount. A crime, but that is another topic).

It came to me rattling around in a micro box. The pedestal had broken loose from the box (don't blame the glue!) I think the original mounter was hell-bent on hiding the pedestal, or was just not thinking, but at any rate, it was doomed to fail with that heavy chunk of sulfide sitting on top.

What I try to do is to pick a pedestal with a base about the same size as the mineral it is supposed to support. Then I taper the pedestal (quick and easy to do with a sharp knife) so that the top of the pedestal is just concealed beneath the specimen. Notice that when I am done, the piece will stand up on its own base. Most of the bottom part of the pedestal will end up getting cut off later when I trim the whole assembly to sit at the correct height in the box.

I have two guidelines that are only rarely violated. First the specimen should be able to perch on top of the pedestal without glue. Second is that with the specimen attached, the assembly should be able to stand up on its own. If these guidelines are followed, a sturdy mount will result when glue is in fact applied.

Viewed under the microscope, the depth of field is so limited, even at low magnifications, that the bottom of the pedestal, if visible at all, is entirely out of focus and in the dark under most illumination systems). I used to fret that pores and cracks in balsa and corks were not blackened when I use a marker, but for most mounts this is simply not an issue.

An exception to all of this are mounts of tiny pieces or single crystals. Mounting these requires a special set of skills and techniques and much of what I have said thus far does not necessarily apply to this specialized game.