I tend to write rituals slowly. I think about it a lot first, contemplating themes and possible activities. There's a lot of research too, often with a lot of false starts... I still have a lot of notes about lichen from an Imbolc ritual that ended up going in a completely different direction.
When the ritual starts to come together in my head, I open a copy of the most recent standard ritual format and start filling in the opening and closing first: the customization of the quarter calls and invocations. The actual writing of the centre section is relatively quick after that, but still can take a couple of hours and several re-writes. Then I make any cue cards and special tools, email the participants a copy of the ritual and any background information, read over my parts a few times, and then finally set up the physical space. By the time we are assigning roles and doing our territory and consent acknowledgments, I have probably spent between ten and twenty hours working on the ritual.
When the actual ritual is going on, I don't always get to immerse myself in the experience because I am leading the activity, monitoring the energy, reading the meditation, but that's fine because I've already spent ten or more hours engaged with the material. The problem is that when I am doing the ritual for participants, they haven't spent all that time. Even if they read the ritual before arriving (always optional) and follow my research links, they are less invested. Even if there's preparation homework, it is still less than what I've done -- as it should be. All of that is to say that I do the ritual in my mind a bunch of times, so when the performance comes, it seems very short.
The bigger problem is that the ritual is short. It is short and it is fast. Since it is the x-th repeat for me, I tend to flow through the plan like it is a rehearsed business presentation. I have to force myself to let the ritual breath and to give the participants enough time to get into it.
Even with that effort, the ritual contracts in physical experience from where it is in my mind. I can live with that; I think it is a common experience of artists that the end result can't quite live up to the inspiration. However, I have to stay aware of the physically performed ritual as it is actually happening and keep it separate from the one in my imagination. I am trying to speak a bit slower -- I tend to talk fast during anything that resembles public speaking -- and I'm learning to count out silences during meditations. But I also need to just stay more present with the ritual and with the participants... it is a tough lesson to learn for someone who lives so much in her head.