My favored tactic is to – Bam! Expand the court to 11 in one year, than 13 in two. Nuke the filibuster if you have to.
Then Democrats can sit down with Republicans and say “You can let us appoint 4 justices to lifetime terms and wait until you get the Presidency and both houses of Congress to expand it more, or you can work with us to pass an amendment to set up term limits and other reforms so the SC is no longer a political football”.