1. Be aware that true ceramic coatings are generally NOT something for beginners. The application itself is not the issue, but that ceramic coatings are NOT forgiving. If you do something wrong, i.e. leave a high spot, you‘ll need to be able to polish those mistakes away. If you feel comfortable polishing, then I think you‘re fine trying to apply a ceramic coating.
2. Make sure you use an actual, real and true ceramic coating and not something that the manufacturer claims to be a „ceramic“ or „coating“ when it is NOT. Some examples of products which are NOT ceramic coatings: Chemical Guys Hydroslick / Hydrocharge / Hydrospeed, Turtle Wax Ceramic Spray Coating, Adam‘s Ceramic or Graphene Spray Coating, Hydro Silex, Shine Armor, F11, Nexgen or any ceramic that is sold at big box stores.
3. Prep work is important for any protective product. With ceramic coatings, it‘s vital! It‘s perfectly possible to apply a coating to an uncorrected car. And maybe the coating will perform just as well as with paint correction. However, there is a proper way of doing things when it comes to coatings and that includes paint correction first. Because it‘s not just about making the paint look better, but also to ensure a perfect „canvas“ for the coating to adhere. To perfectly prepare a car for a ceramic coating, you need to prewash, was, decon, clay, polish, and degrease. The removal of any residue after polishing is key. Make sure you use a panel wipe / IPA that completely removes everything. It‘s a popular misconception that any panel wipe / IPA will remove every polishing residue! The safest bet is to use the panel wipe provided by the same company that does your prefered polishing liquids. Another rather safe bet is Sonax Prepare.
4. Don‘t use an AIO (all in one) polishing liquid (e.g. Autoglym SRP, Menzerna 3in1, Koch Chemie P6.01, 3D Speed) and don‘t use glazes or prewax cleaners (e.g. Poorboys Black Hole, Dodo Juice Lime Prime). Those products will interfere with the coating‘s ability to bond to paint. Panel wipes / IPA won‘t completely and 100% reliably remove everything that those products leave behind. So-called „primers“ like CarPro Essence or Gyeon Primer are a different thing. However, I would absolutely NOT recommend to use them blindly. Only use CarPro Essence with a CarPro coating for example.
5. I would absolutely NOT recommend to apply a ceramic coating outside. The issue is not the application itself. Yes, there maybe are some issues with wind and dust, but that‘s managable. The real issues are temperatures, humidity and curing. Those things change outside which means the ideal flash times change when you work on a car. And that by itself can be an issue. If you don‘t realize this, you‘ll leave the coating on for too long or too short – and loose performance or run into removal issues. Plus, pretty much all coatings need a cure time of 12-48 hours. And that‘s the real issue, because even IF you manage the application and removal in changing temperature and humidity levels, you won‘t be there to overlook the curing process for the next 12-48 hours. If a car is parked outside, it will see MASSIVE changes in temperature and humidity levels. So much that it is perfectly possible that it gets so cold at night, that water starts to build on some (thinner) panels and if that happens, the curing process will be irreversibly hindered. At that point, the whole application was for nothing!
6. The actual application is easy: apply some drops of your chosen coating to an applicator (cotton, suede or microfiber), then apply it to the paint in a crosshatch pattern, let the coating flash, wipe it off with towel(s), go to the next section. The difficult part are variances: some coatings can only be applied to a comparably small section at a time, some can be applied to a whole panel. Some coatings flash in a few seconds, some can be left there for several minutes. Some need a lot of (fresh) towels, some not. Always follow the manufacturer‘s recommendations. As a rule of thumb, i.e. if you do it for the first time: work in small sections and don‘t leave the coating on for too long. Most coatings will „show“ you when they are ready to be removed by creating a rainbow colouring effect. Use several towels for a whole car and one fresh towel side per panel, always working with two towels: one to remove the most residue, and a second one to „level“ the coating. Use circular motions because otherwise you just push the coating around and create streaks.
7. Use high quality microfiber towels for the removal / levelling part. Don‘t cheap out just because you know that you need to throw those towels away when you‘te done.
8. Once you‘ve coated a whole car, drive it outside into the sun or use a good light to check for high spots and streaks. If you see them right after the application, you can correct them by reapplying the coating at that spot and then level it again. The fresh coating with its solvents will loosen the firstly applied coating and remove the high spot.
9. Let the coating cure in a garage or otherwise safe place in which temperatures and humidity levels stay constant for 24-48 hours. Don‘t use chemicals for 7-14 days after application depending on the manufacturers instructions, and that included car shampoos.
10. If you are afraid of waterspotting issues, then don‘t use a ceramic coating. It‘s that simple. Because EVERY ceramic coating is inherently at risk of seeing waterspotting issues.