Not a denominational thing.
A Prayer Shawl can be made by any religion anywhere.
What counts are the prayers the stitcher prays while stitching it whether it be crocheted, knitted, woven, or sewn.
When I make them, I pray for the Lord's will to be done (we know not everyone will be healed), strenghth, courage, wisdom, contentment, to find joy in the little things, guidance, protection, etc. And if the person is a non-believer, that they may find mercy, grace, peace and love in His mighty hands. Another thing is, we always include a card we made up that explains a prayer shawl, has a prayer, and the person who made it along with the date that it was made. We also have washing instructions on the back. If when they feel the need to pass the shawl onto someone else, to please do so with our churches blessing.
Almost every Sunday we have shawls someone has made and pastor blesses them. He has the children come up first followed by the adults and has the children, one at a time, put the oil on their index finger and place the sign of the cross on the shawl as he says the blessing. It is a great way to teach the kids about giving and being a blessing to others.
Guess I should add that the books denote that the different colors (especially of the yarn used) mean differnt prayers. It is up to you what you want to do.
Personally, I like to get my yarn and hook, sit down and let the Lord guide my hands for the design as He knows who will recieve it and what they need. I don't go with the theory of this color stand for this and that. However, our church likes to stick with thedesign I mentioned in a previous post on here, so when mine are for church ministry I follow their design and for folks I especially want to give to, my design. They all get prayed over and blessed. Yes, even the fleece ones I have made per request of the patient.