I am working on a prototype of a project and it involves an antenna. This means that I will probably have to tune this first version a little bit once I get it assembled. To do this, I wanted to place into my circuit a "dummy" capacitor. I realize that I could make a pads in the CAD with the right dimensions, but this wouldn't show up in the schematic. Also, I have seen in schematics capacitors with DNP values. This is what I am essentially looking for. Is there an easy way to do this/best practice? I am a student trying to learn the right way to accomplish these tasks..
The correct way to do this is with variants, as others have pointed out. Do not use the 'Type' property. For every project I have a variant named "Only Populated Components" which makes it super easy to DNP components. Not populated components should NOT appear on the BOM, as this will indubitably lead to questions from the CM. They should also not appear on the PCBA assembly drawing.
A good sanity check to see what is populated and what is not is to view the PCBA in 3D; you can tell at a glance which components are missing.
The preferred method for this functionality seems to be the component's
Type property. Specifically, I think you would use the
Standard (No BOM) part type for the capacitor in question. This means the part has electrical information and is synchronized between the schematic document and the PCB document, but it will be ignored by any BOM generation.
See Altium's documentation page on it.