At the moment you can only create a folder, a text file and a bitmap file.
We should change the two file options for a Create file-option, where you can specify the file extension.
I made a small concept of the file creation dialogue.

If the list gets too long you could maybe use a list view with grouped headers
I really love it.
Filename:
I wonder if we can include a option to specify the filename somehow. So instead of a 2-step action (creating a default file, name it accordingly) it is a 1-step action (both in 1 dialog).
What about adding a textbox at the top for the filename?
Folder:
Can we somehow integrate the folder option? If not, we would need to "new"-buttons (file, folder) or a 2. dialog before this one.
Specify custom type:
We should include a way to specify a custom filetype.

Either a textbox on the top or like this when you click (but I think first one would be more user friendly)
I once saw a control, that would suit, but i don't remember where, so i do my best to describe it.
It is a control , which is divided into two parts. The 1. (left) part is a simple TextBox for the filename and the 2. (right) part displays the file extension (not editable). So as a whole it displays the filename + extension. The file extension is controlled by the selection on the list.
The disadvantage of this control is, that it doesn't work nicely with the folder type.
so like this?

Yeah kind of
I'm not sure about where the create button should go
What about a simple drop down menu that fetches the options from the registry?
too simple 馃槀
i really would like to have an option to specify custom filetypes.
With explorer i have to create a textdocument, so i can then rename it to a markdown file.
yeah you're right, thats annoying. but maybe just put it in as first/last dropdown option
For me personally the custom entries in the explorers "new"-menu do not bring any value.
The only option is use are the "folder" and the "textdocument" options.
I create all other entries (office, zip, bitmap) through the corresponding apps.
You should be able to specify a custom entry. A AutoSuggestBox, where you enter custom entries. Or there is a settings option or a json file, where you can specify custom entries for the dropdown.
Merging with #507.
Most helpful comment
For me personally the custom entries in the explorers "new"-menu do not bring any value.
The only option is use are the "folder" and the "textdocument" options.
I create all other entries (office, zip, bitmap) through the corresponding apps.