I have a bag that attaches between the two handlebars & holds a good amount of convenient stuff. I got it about 25yrs ago, when I bought an '84 Yamaha Venture that it was on. I have(now) used it on 5 bikes. It has now name or brand on it. So, i cannot give you a recommendation of where or what to look for, but I have used mine quite conveniently.
I've gone through all of my pictures & none of them show it well, or at all!
I can tell you that it attaches with 4 velcro straps to the handlebars & that it has a velcro closing flap at it's top/front.
Today, I wouldn't be without it. It hold my comb, multitool, asthma inhaler, chapstick, etc. In close reach. Most convenient.