Funny you should ask about hibiscus. I just learned how to make them out of royal icing. You use the largest lily nail, line it with very thin/cheap aluminum foil (foil candy wrapping squares are great). Using petal tip #104, you pipe in five large petals--start at the bottom with the wide end of the tip touching the bottom of the nail and come up, round off over the edge of the nail, and go back down to the bottom. If you stripe the bag, you get a nice central line color change and don't need to pipe tip #3 lines up the center--unless you want to. You can dig out the surplus icing in the center--halfway to all the way down to the bottom of the nail (I use a thin paintbrush handle to do this) and then pipe in a tip #5 yellow or orange stamen--fat at the bottom and tapering at the top and as tall as you prefer. Set the flower aside--on it's still foil covered bottom with the stamen up straight or at the angle you want--and when the stamen is pretty dry, pipe about five little tip 2 extensions off the top of the stamen. These will need many days to dry through, but you can get the foil off pretty easily around day 4.
In the photo, you can see a yellow one with a blue stamen, a pink one, and a blue one. Each was made by a different person, so they vary slightly, but you can tell what they are
Hope this is helpful and clear.