Once the leaves are in place according to the counted thread chart it is easier to place the flowers.
I suggest you work the dark purple flowers on either side first, then add the central lighter flowers, and finally work the flower centers with your palest color. When working small sections of cross stitch in this scale, it is sometimes easier to see the threads if you work only one cross at a time, instead of working entire lines by going in one direction, then back in the opposite direction.