I made this flag holder that a small flags vertically. I printed it at 50% infill to make it heavy and sturdy however if you don't want to waste material you can just use 15% infill and it still works fine. This print requires no supports. The flags stick in nice and snug and don't fall out. If you want a holder that hold two check out my other design here:

https://makerworld.com/en/models/390044#profileId-290981