Question: Is there a way to export photoshop/Illustrator files to .ttf or .otf files? I know there is no option for it in these programs themselves, but perhaps there is a third party program which can import them?

Are programs like Glyphs or something the only way to make fonts? And how do professionals make them?

Hope you can help

Answer: 
FontLab (commercial app) can import Illustrator paths: <http://www.fontlab.com/contact-and-support/faq/faq-fontlab-typetool-mdash-glyph-drawing/> . FontForge (FOSS) can as well, and apparently some other vector formats: <http://fontforge.org/importexample.html>

As for the second part of your question: most professionals use tools such as FontLab, Glyphs, RoboFont, etc. and draw directly in the font-making applications. In many cases they will work from a template/background of some sort, such as a scan of hand-drawings, or perhaps outlines of a different weight of the same design, etc.
If you are looking to make an Icon as a font then this guide will help.

The easiest way is to use a great free online app called [IcoMoon](https://icomoon.io/), by Keyamoon, which takes away all of the hassle of converting symbols into a web font. Click RED button on top "ICO Moon App" and just go with the flow.

For Step by Step guide for doing the conversion you can follow the below link:
<http://www.webdesignerdepot.com/2013/04/how-to-turn-your-icons-into-a-web-font/>