You nearly got me! I was about to tell you all about rooting roses, but this is a Hibiscus, right? I think you will find it difficult to root at this time of year, much easier in later spring when the plant is growing strongly. Try it in a 50/50 mix of soil and perlite, or a similar well-aerated type of soil. Just take about 6" from the end of a vigorous new shoot, older wood should be treated as a hardwood cutting. You might want to try hardwood cuttings at this time of year but the technique is completely different.