Hi @summer,
Thanks for your interest! We are still in the process of improving documentation for new design contributors, so I apologize for the lack of info so far. This is the thread where we have been discussing how best to do this (your input is welcome):
What I would recommend for now is that you first get acquainted with OpenRefine as a user (if that is not the case already): you could watch/read some tutorials about it and use it on a dataset you are familiar with.
Perhaps in that process you already encounter things that are counter-intuitive for you, workflows that could be improved, interfaces that could be made clearer… if that is the case, it is super useful if you give us this feedback. It could be on this forum (for instance in the Support category if you are not sure about something), or you could file a GitHub Issue directly.
If nothing catches your designer eye after using OpenRefine for a bit, then you could look at those issues that others identified:
- In the facet box display the facet expression used · Issue #745 · OpenRefine/OpenRefine · GitHub
- Delete multiple projects at once · Issue #4965 · OpenRefine/OpenRefine · GitHub
- Custom facet names · Issue #1011 · OpenRefine/OpenRefine · GitHub
- Option to exclude some candidates in a cluster from being merged · Issue #105 · OpenRefine/OpenRefine · GitHub
Those are issues where it would be useful to have a designer propose a particular bit of user interface to address the need. You could pick one and propose something there, for instance with mock screenshots made with the tool of your choice, or describing the desired interface in any way you like.
Does that help?