Ask as many questions as possible. Ask the project manager, site manager or operations manager. You can even ask me if you are not satisfied with their answers. Point out things that bothers you, and be vigilant for mistakes. BUT, don’t do it while the guys are still in the process of application and the products still need to be floated or finished off.
If you can see that something is going to be skew, or blatantly not right, please speak out. Tell the manager on site that this is worrying you. This way you can save yourself, and us from a lot of frustration and extra cost. Don’t leave a problem until the end of the project, and then ask for it to be fixed, it will probably make things extremely difficult to rectify at that stage, but also, don’t be too overwhelming, because that has a tendency to make the applicators uncomfortable – a recipe for disaster.