I use the Kodak E6 Single Use Chemistry Kit for processing Ektachrome 35mm to 5"x7" sheet film and have found it easy to use and almost foolproof is you follow the Kodak instructions. I have attacthed a link to the Kodak site if you haven't already checked it. For sinlge shot use sometimes it is adviseable to decant the developers and replenisher into smaller bottles to reduce oxidation or putting an inert gas into the bottles to displace the oxygen in the bottles to extend the shelf life. Kodak recommends that you use the kit within two years of the production date on the bottles. The most imprtant thing I have found with E6 processing is being able to keep the temperature as close to Kodaks recommended times as possible - especially for the developers.