How to recognize a spirit's presence
To detect the presence of spirits at your home or ritual space is crucial ability. It is crucial for the success of the operation, it is crucial for your health, your sanity, and it can be crucial for saving your life, as well.
When things fall from the table, television switches on and off no matter what or your wardrobe sings, it certainly means there is some spirit present (or it can also mean you should stop doing drugs). The thing is that this usually doesn't happen, spirits do not usually levitate tables, pets, mother-in-laws... they do not break vases, windows, they do not turn on and off TVs and they certainly won't pay for your cable to watch adult movies. It can happen (and sometimes this happens during the rituals), but most of the time symptoms of having a spirit companion are more subtle.
The flow of a wind in closed room, feeling like someone's watching you from behind, tapping your shoulder, touching your back, sometimes there are also marks from scratching, but these are somehow attracted just to sensitive individuals. All these can have alternative reasons. E.g. the window lacks the isolation which explains the breeze, feeling of being watched from behind is intuitive process that happens during the night, scratches can be from your own hands when you were scratching your own back, tapping can be a little mischief of your neural network. During the spirit's presence there is usually more than just one symptome.
During spirit's presence there are more indicators, one of them is a changed quality of sleep. You usually have to sleep more, you always feel tired and even shortly after you woke up, you are out of energy. Lack of energy PLUS wild sex oriented dreams can mean the presence of a succubus or incubus, simply sexual demons. These demons use sexually oriented images, visions and dreams to rob you of your sexual energy, your vitality and even your sexual desires.
External verification method
It is a good idea to have some external verification, as well. Something that isn't based on our feelings and ideas. Do you feel tired after waking up? Well, maybe you just didn't sleep well enough. To verify if there really is some spirit that haunts your environment, put a glass of water on the table next to your bed, you can put a lid on it, it doesn't really matter. If there is a spirit in your house, the water will be full of small bubbles during the morning. I know this can sound stupid, but it really works. If you find bubbles in the water, do the banishing ritual and try once more. Next day use new water and check it in the morning. The result will be different.
You can also try this test for your rituals. Someone explained to me that presented spirits like "refreshments" during rituals and bubbles will appear in no time if your evocation goes smoothly. Sometimes it happened to me that bubbles appeared in a matter of minutes when I was just talking about spirituality with my apprentice, sometimes bubbles didn't appear during the whole ritual and the result was usually a failure then.