filemaker 15 pro
1. are you looking for button icons that are NOT built-in?
a. if you are looking for icons, search for icons (some are free) that are JPG or PNG. these web icons will work in FMP as well
b. if you are looking for icons that are SVG, you can search for those as well. if you need these to work with FM (conditionally):
2. are you looking for just the style of the buttons (with or without icons)?
a. have you tested the various themes available? each one has different design.
b. there are custom themes that you can create:
can i use button you made it?
You can Insert (or copy) any elements. What you get when these are from someone else depends greatly on several variables. If you have icons that you copy and paste, then you have them available as they are just graphics. You can also import new button icons (see the button dialog).
Keep in mind that if you have a chosen theme, then it will have default styles for the buttons. If you import/paste any other 'styled' object (button, for example) it may not look consistent with the layout's theme.
Also a button tend to have script or script step attached to it. If you copy/paste a button from someone else, the script will be "<<missing>>".
Have you checked out the themes available?