Here's a tip for men (and the women who love them)
In our culture it's common for men to have problems with erectile dysfunction. This is often caused by tight muscles in the groin preventing sufficient circulation to that area. I think this is because we sit on chairs for many hours a day, instead of squatting with our heels on the ground as they still do in other cultures and as our ancestors did. Squatting naturally stretches out the relevant muscles. If you're having this problem, try squatting for a few minutes a day.