The decision to use ritual in our work is a very personal one. Some find that ritual enhances their work – candles, incense, prayer, group work. Others use little or none.
Usui Sensei himself used little ritual or structure. After his death, his students introduced the hand positions, the use of the symbols at the advanced level and the different levels of practice to give some structure to what is essentially an amorphous practice. You may find that bringing ritual into your teaching is helpful to your pratice.
The role of ritual in Reiki, as in religion, is to help us focus our intention. Our Reiki practices are unique; everyone interprets the work differently and our practices develop and grow through the lens of our personal experience, encounters and relationships. Our Reiki practice is very individual and will change over time. The rituals we use may also change, or fall away.
I have found the protocols of grounding, protection and invocation to be very helpful in my work. You may choose to adopt them, adapt them, create your own, use something else, or use none at all. All of these options are fine. The core of your practice is your intention.
Never let anyone tell you you’re not ‘doing it right’ just because you don’t use the same protocols as s/he does. Your practice will deepen and become enriched through your experience, and will be right for you.