I created my templates on powerpoint with a fancy font and colour. The fonts I brought were off teachers pay teachers that I uploaded onto my computer to be able to use. You then save your text and background as an image, and upload it onto google keep as an 'add image'. It will then save it to the top of your note.
There are lots of other great ideas floating around the internet but I hope this helps unpack it easily on how you can make it pretty yourself.
Mrs Priestley ICT blog is a place to read, download and view ideas!