It's Stop the Bleed month, so it's time to share resources! As an EMT, if I could only teach everyone one thing for emergency response, it would be high quality CPR. If I could teach them two, it would be CPR and bleeding control.
This is the most useful single resource, imo:
https://www.stopthebleed.org/-/media/stop-the-bleed/files/save_a_life_flowchart.ashx
https://www.stopthebleed.org/-/media/stop-the-bleed/files/save_a_life_flowchart.ashx
Here are the two things referenced in the flow chart as ideal if you have them.
Hemostat gauze: https://www.rescue-essentials.com/celox-rapid-b-con/
Tourniquet: https://www.rescue-essentials.com/combat-application-tourniquet-cat-7/
Hemostat gauze: https://www.rescue-essentials.com/celox-rapid-b-con/
Tourniquet: https://www.rescue-essentials.com/combat-application-tourniquet-cat-7/
Get them, keep them in your car. If you're going somewhere where having them in your car isn't helpful, like a protest, you can carry them in one of these: https://www.rescue-essentials.com/rescue-essentials-ankle-medical-holster/
Catastrophic bleeding is one of the most depressing causes of death because it's so common and so often meaningful intervention could be done if bystanders just had the right training and, ideally, equipment
If you want more details than the one-page flowchart offers, this booklet is great: https://www.stopthebleed.org/-/media/stop-the-bleed/files/basics_of_bleeding_control_booklet.ashx
If you work for an institution that has first aid kits on site, push for them to add a tourniquet to each, and hemostat gauze too if it's possible for your budget.
(Hemostat gauze is especially important for churches and other places where there's a higher-than-average chance that the person needing care will be older and possibly on blood thinners. Celox will clot blood that's been treated with warfarin.)