I have created a content type with about 15 fields.
I'd like to improve the layout of the form for creating content of this content type.
Currently all the input fields are listed one after the other which means a lot of vertical scrolling and not everything can be seen on one page.
I looked at the Display Suite module ( http://drupal.org/project/ds ) but I could only see how to layout the resulting content not the input form used to create it. (UPDATED: answer below from Елин Й. says that display suite can actually layout the input form)
Another option would be to create a theme with form layout (good question - and answers here: How to a use a template file to theme a form? ). That's fine, but before I do that I wanted to look at other options available (don't wish to re-invent the wheel.)
Or should I use entities and EntityForm instead if that provides better layout options.
Finally, I'd prefer not to use webform module as EntityForms and ContentTypes provide better integration with built in Drupal features, so I've read.