I think an effective way of contributing to a social matter is speaking out about this. In real life conversations but also online on social media, it can be effectively used to create awareness.
-Attending (peaceful) protests
Look at the example of George Floyd, the amount of people that spoke out about this on social media and the series of events it brought. By protesting there is of course initially no solution to the problem, but what it does do is raising awareness. This way it stays a topical issue, bringing the subject forward and perhaps create a shift of consciousness. To refer again to the BLM-movement, this movement has been contributing in The Netherlands to change the tradition of ‘Zwarte Piet’, also known as ‘Black Pete’. A caricature that is a servant of ‘Sinterklaas’, bringing presents on a children’s holiday, imaged as a black man. It took many years, but by keeping the subject alive every year, even more conservative parties are getting aware of the suffering that goes behind this caricature.
Even though it can sometimes difficult, I do believe that by keeping a respectful conversation, a lot of understanding can be brought up for both parties. Keeping an open mind and truthfully listening would combat a lot of polarization. Here an example of that again (I’ve shared this video here before on another topic).
At last, I want to give an example of how I tried to support a good cause. Even though I am not vegan myself, I do think this is a kinder way to treat animals and that it is an important movement specially to create a smaller environmental footprint. I try to create awareness about this by talking about it, and showing plant-based alternatives. On my birthday I have cooked a vegan three-meal course for 30 people to show them that it can be easy and delicious as well.