Thoughts on the way spirits present themselves:
Sometimes, when we're calling spirits, they're arrive without us knowing. The spirit could be standing right in front of us waving, and our subtle senses just aren't fine-tuned enough to see them. Some get around this by working with a scryer. Others might build the ritual pressure in the space until the spirit is compelled into become more visible. Something i find consistently reliable is utilizing forms of passive divination.
This way, you have ways of diving a spirit's presence without having to pull your attention away from your conjurations or ritual actions.
Passive divination methods for spirit conjuration could include:
Burning incense to see figures and signs in the smoke
Letting candles melt to look for symbols in the wax
Hanging bells around the space
A water scrying set up where the surface is oily to more easily produce images
Above, I included photos from a ritual I did a while ago where I used candles and stone with a similar purpose. This stone was being consecrated as a tool to scry with in the future, and I wasn't receiving clear signs that the spirit i called had come. It wasn't until I looked down and saw the melted wax in the form of a black hand that I realized they were sitting with me. It was small and very subtle, so subtle I could've easily missed it.
Having passive ways of scrying and divining the presence of spirits can be a huge help when exploring new spirits and conjuration methods. It takes some discernment to know how to use them, but when applied well, they are a huge boon to one's setup.