Surface Preparation is Critical to Application Success
Most times with and adhesive doesn’t work, or “fails” it falls under a couple different scenarios. The “is it plugged in?,” the annoying common (to the person asking, and answering) solution is surface prep. You stick adhesive on a dirty surface, and it will fail. This is not because the adhesive didn’t stick, but because it did adhere to the dirt, grease, flaking paint or debris was in between the substrate and the adhesive.
The surface must be clean. Most substrates are best prepared by cleaning with a 50:50 mixture of isopropyl alcohol (IPA) and water. The most common failure of the an adhesive is when it is applied to a dirty surface. It is not that the adhesive failed, it's just that it stuck so well to the dirt that it never bonded to the substrate.
The next step in a successful bond it to remember that these products are pressure sensitive. Once you have them placed where you want them, make sure pressure (ideally with a roller, but your hand will work just as well) is applied to activate the adhesive.
Know your adhesive: A rubber based adhesive will have a high initial attachment, and reach its full strength in a few hours. An acrylic based adhesive will only have a lower initial "grab" when it is first applied. It will take 24 to 48 hours it will reach its full bond. Acrylic adhesive will typically have a lower initial tact than a rubber based, but will have an higher overall bond strength after it is completely set.
Climate considerations: Applying pressure sensitive adhesives in very cold or very hot conditions can lead a poor bond. Many adhesives, after they are fully bonded under reasonable conditions can withstand a wide variation in temperatures. But for optimal preference adhesives should be applied, and allowed to bond at room temperatures. Also make sure that the surface of the substrate is dry before applying your product