Hey Gene, Ever body does it differently, and that is fine, but here is how I use the packing tape. First I only use packing tape on hardwoods. Rarely on Baltic birch or soft woods like pine and ceder. I apply the pattern to the wood with spray adhesive. then I apply a single layer of the packing tape over the pattern. I use a plastic putty knife to burnish the tape, that is using the putty knife as a scraper to push the tape tight against the pattern. This eliminates any air bubbles and prevents saw dust from getting under the tape and obscuring the line.
Now here is something I have never told any of you. If I am cutting 1/2" or thinner wood, If I am not going to get it cut in one sitting, I apply a blank sheet of paper to the back of the blank, then apply more tape as above. The reason I do this is wood tends to cup when you prevent moisture from one side. So to prevent this I Tape the back side. I always use a Reverse tooth blade, so it helps with the back side of the cutting.
After I am done cutting, I spritz the tape and pattern with a spray bottle of mineral spirits, and the pattern and tape comes right off. If there is any residual adhesive on the blank, spritz a little more MS and gently wipe of with a clean rag.