DIY Tint For Side Windows

Has anyone tried fitting pre-cut tint on side windows at home rather than taking the car to an installer? I am not trying to rush the job, but I want to know whether the shaped pieces make the process easier for a careful beginner.

My first attempt was on the rear side glass because it felt less stressful than starting with the back window. I cleaned the glass twice, laid everything out on a table, and only then started fitting the film. Using pre cut window tint made the job feel more controlled because I was not trimming around the edges while the film was already wet. The finish still depended on patience and clean glass, but the shaped piece removed one of the most annoying parts of the process.