Generally, I banish before any ritual to prepare myself and my space to the ritual dependently if the book say banish or not. And banish going to sleep. Some nights when I feel a strange energy that I don’t identify I use the frequencies all the night while sleeping. I use this book and its very powerful and I had very good results with it. Also, there are parasites or imposters can attach to the ritual if you don’t banish. What I always try to do when I work with an entity, I try to ask him o identify its energetic seal o feel. For example, the energy of Lucifer feel like a cold ice in your left shoulder. Also don’t try to control any entity because this miss up the work. Approach them with not fear, respect and honesty. Some entities before working with you they will test your mental, emotional and spiritual strength and they will teach you in the hard way.
As you say, the experience and the practice is the best teacher. ‘Without adversity, there would be no growth, and without growth, there would be no lesson to be learned.’ D. Rosado. With this experience you will learn a lot. You are more strong than any impostor or parasite. Only rise your vibrations and mediate.