Make the petals like the leafy grass in the tutorial here. Make sure all the loops are of the same size and make a maximum of 5 loops per petal for the above flowers.
Make 4 such petals.
Score a line in the middle of each strip with an empty ball point pen or similar instrument.
Now fold the 4 strips using the score marks. Use the valley side of the score mark to form the valley of the fold.
Now apply glue to the stems as shown and glue to another petal and make 2 half flowers. Now flatten the stems so that that stems of the two halves can be glued, and glue them together to make the flower.
Apply a tad of glue to the center of the flower and make your hand into a fist and place the flower into the hole made by your index finger and thumb so the head of the flower with the glue faces up and sits on your fist. Take the blunt end of your quilling tool or a stylus and apply pressure downwards so that the head of the flower shapes into a cup and allow the glue to dry or you can shape it with your fingers as shown.The important thing is to allow the center glue to dry in a cupped position. Once this is done you can glue a center on top and a few pieces of yellow strips in between the petals to form the center.
Now apply some clear drying glue to the stem and twist it tight and allow to dry. Once dry you can make the green stem starting at any point. As shown coil it around a few times and glue it then start twisting it down with the strip diagonally to make the stem as in my tutorial here.
That's It !! you can use this method for flowers using quilled petals as well as it is very firm and these flowers can be placed in quilled vases.