Hi, does anyone have any tips on how to customize a form within a landing page to make it look more elegant? Change the style of the button? Text? anything beyond what is in the basic form editor?
when creating / editing a form, on the form settings -> form theme, there is a button. You will be able to edit the CSS of the form. You can also add some CSS to your landing page template.
You can write some CSS to style the form. I wrote about some tips in this post: How To Style A Marketo Form Like A Pro
"Elegance" is hard to pin down. There are tons of Community posts about form customization for you to search.
You can start from scratch using my destyled Marketo form: MktoForms2 :: Destyle Marketo form. Another core task is tagging generic wrapper elements so you can style them based the fields they enclose: MktoForms2 :: Tag Wrapper Elements
Depending on your needs, you can also alter the default HTML markup. I do this in a lot of the demos you'll find here.