I use carpet tape when a template is used. Whatever is available from Lowes when I need more.
I use vacuum grips to hold the work piece down while routing or working the edges, also when carving sometimes. The Rockler Vacuum Chucks are what I mostly use, but I have made some DIY vacuum chucks, using closed cell foam Weatherstrip on a solid base of cabinet birch ply or HDPE (repurposed cutting board). The vacuum pump came from Harbor Freight, and I added a filter to keep saw dust out of the pump. It takes a pretty hard hit to break the vacuum grip. I usually just shut the pump off when the work on the piece is finished. A few seconds later the vacuum is gone and the piece is free.
Charley