Banana joint leaf pointers: You get some dry banana leaf, like the leaves that are dead and falling off the plant. If it's brittle, wet the leaf and work some moisture into it so it's flexible. Then cut it to the size you want. I roll it up real small and tight from both sides of the leaf; rolling perpendicular to the grain of the leaf. It should take on a joint/blunt wrap shape. Then set your wraps in the sun and let them dry out and they should hold a nice shape so that you don't need any glue or anything. You can put your flowers in after it dries. You can probably put them in before it drys too, I haven't tried it though. You can fold or cut/tear small strips of leaf too to make a crutch too.
My buddy told me some of the Filipinos here just smoke banana leaf and it supposedly has some effect. I've never smoked it straight so I can't verify that, but I did get really high off the Jamaican Goji OG I was smoking in a banana leaf wrap yesterday.