I'm and upholsterer (since 1966) and have been making upholsterered cornices for one decorator for over 10 years. We have a real good working relationship. I respect her integrity and her professionalism. She respects the quality and preciseness of my workmanship. She and I have talked through and planned out the making of many cornices.
Today I'm making another cornice, which will be covered in a vine pattern, with branches coming off the center vine. I called her to discuss where to place the vine pattern. Since she wants to vine to run horizontally across the face of the cornice, she has three basic choices. I had previously laid the fabric of each choice on the cornice to see what each choice would look like:

• a.) Put two vines running horizontally. With this pattern placement, the pattern is too wide to have a full width of both vine patterns. So part of the upper pattern will be cut off along the top edge and part of the lower pattern will be cut off along the bottom edge.
• b.) A second choice would be to center one vine horizontally in the middle  of the cornice height. Since the branches of the vine pattern are much longer on the top side of the cornice than on the bottom, the width of the pattern would not be centered. Also the branches on the adjacent pattern, top and bottom, would be longer on the bottom than on the top.
• c.) The third choice would be to center the full width of the vine and branches horizontally across the cornice. This would mean that the center vine would not be center, but be below the center of the cornice. However, the branches on the adjacent  patterns would be evenly spaced an even amount top and bottom.

After I had explained her 3 options she asked me for my recommendation. I told her that I liked choice c, and I explained why. She told me that it sounded good to her and that she would go with my recommendation.
In a very real sense she would acting on faith. She couldn't see what the pattern placement would look like, but, because of long association and her having seen the results of my work all these years, she had faith in my recommendation. I know her and I made a recommendation based upon what I thought would give her client the best job.
Her faith in me wasn't something that she instantly decided to "have faith" with no substance and no history of proven quality and trustworthiness on my part. Her faith was based upon something real.