Between my meatspace identity and Mirimir, which is my least ~anonymous persona, well-mixed means mixing successively by three different services: A, B and C. I mix via Tor, using Whonix VM instances, and Electrum wallets. So three Whonix/Electrum instances: X, Y and Z.

    source to X via A
    A to Y via B
    B to Z via C

Bitcoin in Whonix/Electrum instance Z is available to spend, or transfer to another VM.

For transfers among ~anonymous personas, I just mix once or twice, depending on the desired compartmentalization level.