Who do I ask for a reference after a layoff? - what worked for you?

My manager was laid off too and I am unsure who to use as a reference. I do not usually post, so bear with me. A colleague offered to vouch for me. Who did you use?

Ask former colleagues and supervisors in a short message and give them a summary of the job you are applying for.

A client reference worked well for me. It shows you deliver outside the company too.