Let's go beyond just the men calling out other men thing on here. Here are a bunch of other things I think we all (including men) could be doing. it's obviously, tip of the iceberg:
Schools and parents not buying into "boys will be boys" when it comes to rough housing on the playground, especially when it's aimed at the girls. No more "he pokes you because he likes you" etc. Similarly, let's stop telling the girls they can't shout - DD had a skin tag that a boy kept touching but she was too scared to shout at him to stop when he ignore dher because she was told she wasn't allowed to shout.
Active teaching on consent and the reality of men being (usually) physically bigger. DS is a tall child - he's 13 and 5:10 already. He has always been taller and bigger than the children around him so from when he was about 2 I started explaining to him that if he's playing with another child he has to be thinking about how the other child feels. I have mentioned this on the playground a few times and had horrified responses.
Let's also not be coy about sex and reproductive education etc. Our children are seeing and feeling this stuff. Saving the tough conversations until they're 16 is too late. We don't only start teaching them about road safety when they go to high school and have to walk = we start when they're still in their prams, reminding them to look both ways. Periods are normal and not shameful and should be openly acknowledged from a young age. Condoms are normal and essential. Sex is fun... at the appropriate age and stage. normalise these things from a relatively young age BEFORE they're being influenced by social media and other uninformed teens.
Role model men ACTUALLY stepping up. Taking on their share of childcare and household tasks. Taking responsibility for things in the home and for children. Identify and highlight positive role models, male and female, at home, at school, at work, in public. Similarly, don't drag women in public down. Really really stop and think before you disparage that woman - is the disparagement real, or is there some unconsious bias there? Never ever make disparaging comments about women BECAUSE they're women "oh, women are a bit silly about this stuff - don't worry about it." Support women in leadership roles and aim to have more of them.
In the workplace, if you have power, support women who have caring responsibilties. AS importantly, support the men. Make the culture one in which neither are penalised for caring responsibilities and both are encouraged to use any flexible working or similar. Similarly, consider how you talk and think about women in your organisation. Really examine unconsious biases. Are you networking with the women in the same way you do with the men? Do you have to do that golfing event? is it excluding a bunch of women?
If your local council is considering changes to its playgrounds or facilities, get involved. Find the research on making these spaces welcoming, and safe, for girls and lobby for the change. Start by taking a look round your local public spaces and tell me if you see anywhere near as many girls as boys? I bet you don't. Be angry about that. Lobby for change (this is next on my list in my area).
Is the TV youre watching passing, at the very least, the Bechdel test? Where else are you finding you're defaulting male around you without even being aware of it? Every man should read Invisible Woman - it's an eye opener and is the precursor to this other shit. Don't talk down about literature, movies, or art aimed at woman - why are "chicklit or romantic comedies" considered less than male-dominated detective series or action movies?
All of these things are small things but that consistently position women as less important, less relevant. frankly, less HUMAN. if we can stop thinking of women as second class citizens, it's an important step towards reducing VAWAG.