Is there an existing template/program/guide to create icons for the Finder toolbar that match the look and feel of the standard icons (buttons)?

The reason I ask is that I have created shortcuts apps in the toolbar for 'create new text file' and 'open terminal here', but the best .icns that I could lift from the internet are still kind of visually distracting.

i.e. I want to create a new .icns file to replace the two right most icons so that they blend in with the others:

![enter image description here](https://i.stack.imgur.com/nAqwm.png)