I honestly hope more people have the courage to stand up to them like this.
Pulling this administration away from its worst, most destructive impulses is going to be an exercise that we're all going to have to participate in. It's going to take some cajones, because heads will probably roll. But the fact that it's the right thing to do, as opposed to pledging blind allegiance to Comrade Trump, means it is still worth doing.
So what can we do? Honest absolutely non-cynical question - I'm calling my public officials, sending post cards and letters to my congress and senate members, marching in protest, donating to ACLU and PP as well as others locally - what are you all doing that I can join? What can we be doing better or more of?
Find ways to create awareness. All the activities you mention are awesome and you are doing more than most. The only thing I could add is find a way to educate and recruit others. Help those that believe they have no voice to realize they can be heard. Whether this is volunteering for a political group or something else. In our current social & political climate, anyone that can be marginalized will be. Empowering people in one area of their life almost always flows to other areas.
Any entity that needs money can probably also use your time. My passion is typically for education-related programs for the underprivileged & underrepresented. The state education dept, local schools, and colleges all typically some type of volunteers in this regard. Your interest may vary.
It boils down to participation, education, and vigilance... You are doing great in this regard.