These are taken from an excellent Australian source. We created highlights and edited them for the U.K. Check out the full article here:
https://psychology.org.au/publications/inpsych/2013/august/louis

Lesson 1 – Focus on change within your own group, not others.

Racism interventions typically bring to mind mass media campaigns, tolerant organisational policies, and training in one-on-one interactions. Yet, all of these interventions can be ineffective if we don’t feel as though the anti-racism message comes from ‘one of us’ (a fellow group member).If people feel like someone from another group is judging them critically, it can make them reject the message–  and for an anti-racism intervention, it can make them intensify their prejudice. That’s why it’s so important that respected in-group members deliver the message and model the desired behaviour.

Lesson 2 – Portray tolerant behaviour as widely supported

Most activists have a strong instinct that emphasising the scale of the problem is important in a campaign (“Racism is everywhere, and must be overcome!”). However, psychological research suggests that this is not necessarily a good idea. People are most likely to accept a message of widespread discrimination if they don’t identify with the perpetrating group. If people identify with the perpetrating group (and after all, this is the group that anti-racism campaigns are targeting), then making salient the belief that discrimination is widespread may make people more likely to engage in the problem behaviour.Even the message “this behaviour is common but terrible and we need to change it” boils down to “this behaviour is common”, and people behave accordingly. We like to do what our group does, and if something is common, and characterises our group’s behaviour, we feel that that we should get involved (even with racism).Therefore, it’s important to draw attention to alternative positive behaviours instead of increasing the salience of prejudice per se. In particular, one should focus on tolerant behaviour being expected, appropriate and morally right.For example, we suspect that recent news coverage featuring one person’s ranting racist diatribe on public transport followed by several people challenging the bad behaviour could have marked anti-racism effects.

Lesson 3 – Friendship Matters

Pointing out racial inequality is confronting for bigots, so the most effective ‘anti-racism campaigns’ may be indirect – those that provide positive portrayals of tolerant interactions between advantaged and disadvantaged groups without drawing attention to their anti-racism purpose. Putting forward racial minority group members as champions or leaders of a larger group may have powerful indirect effects, for example. There is also evidence showing that from toddlerhood onwards, having friends of different races reduces racism and increases intergroup warmth. Even just seeing that intergroup friendships exist can lower prejudice, which is inspiring.Therefore, if you’re from a more privileged background, you can make an effort to have a wide friendship circle and to talk openly about your intergroup friendships.Modelling and communicating inclusive attitudes and actions could be important to spread these norms. This concept of modelling can be extended to the use of high profile individuals in anti-racism campaigns.Seeing popular and respected in-group members engaging in tolerant behaviours can have powerful anti-racism effects.

Lesson 4 – Break up the racist consensus, interrupt silences and claim the group!

What about directly confronting bigoted family, friends and co-workers? The first rule is, aim to break up the racist consensus – don’t be silent. A dynamic in which public racism goes unchallenged makes other people think racism is more socially acceptable than it is, which spreads the problem behaviour.Don’t let that happen – speak up!Don’t leave it for minority group members either – often in a mixed-race group if someone says something racist, the other privileged group members freeze.They think only disadvantaged group members have the right to respond. But that can make it look like everyone’s racist, and put disadvantaged people on the spot.What’s more, when disadvantaged group members speak out they cop social flak. It’s often better for the most socially powerful non-racist person to speak up and show solidarity — that could be you!When you talk, focus on the behaviour not the person, and say something like “No way. I reckon most people would think that …” and carry on from there articulating a positive, non-racist view. Or, “Whoa! What did you just say? We say x instead….” and so on.The good news is your intervention is more likely to be effective if you don’t make it part of a broader, hours-long conversation about your political differences. Ranters get tuned out. Express your anger later, with your non-racist friends. Short, warmly delivered, direct contradiction followed by a positive alternative could be the way to go.

Lesson 4a – Think carefully before calling someone racist

Calling someone racist or labelling their behaviour racist is good if it makes other bystanders less likely to copy them (e.g., children), or other disadvantaged group members feel like you’re standing by them passionately as an ally. But it puts the bigot on the defensive and may make them less likely to change. One on one, you’re better off talking about your personal experiences and what from your own life leads you to think whatever they said is not true.You also can appeal to common values (“Are you giving x a fair go?”) and to perspective-taking (“What would you do in their shoes?”). Acknowledging the basis for their views as valid (“You love the UK and want to protect what we have”) doesn’t mean accepting their view as valid. Listening and acknowledging what bigots say can be an important part of building the relationship trust that may subsequently allow them to hear what you’ve got to say in a non-defensive way.

Lesson 4b – Be in the minority without despondency

Finally, sometimes you’re trapped in a large group of racists whom you have no hope of changing. Should you still speak up? Yes! Take it lightly (you’re not going to change their views that day), but do take the opportunity to fracture their consensus.Briefly and warmly present a positive alternative belief or modelled behaviour. Stress the similarities between you, and then highlight your resistance to what they’re saying. Listen and acknowledge what they say, while continuing non-defensively but persistently to dissent. It may be tedious but it’s great karma – and it will make it easier for their views to change down the track.

Lesson 5 – Politics matter

While we focus above on how individual ARC members might confront racism successfully, coordinated political and social action is also critical for promoting legal and normative change.More broadly, we hope that ARC members can combine personal and group-level support for anti-racism initiatives. We can can play a key role in promoting positive change by progressing personal friendships, taking stands in public, and supporting the interests of minority groups in workplaces, community organisations and political life.