Editing in PixelSugar is simply adding steps to the "recipe" for your photo. The Recipe panel shows what steps you have added, and what order they are being applied to the photo. Steps in your recipe are applied from top to bottom.
Adding And Changing Recipe Steps
When you add a filter from the library, it gets added to the end of your current recipe. You can click on the step in your recipe and drag it up or down to change the order steps will be applied in.
Each step can be applied at a reduced strength, from 0-100. Use the slider to change a step's strength, or type the value you want directly in the text field.
You can also hide a step in your recipe, toggling whether it's currently applied, by clicking the eye icon at the step's left.
Undo / Redo
You can undo / redo any modifications you make to your recipe with the Undo / Redo buttons in the Recipe Panel toolbar, or by using Cmd+Z and Cmd+Shift+Z
Clearing The Recipe
Pressing the Clear Recipe button resets your recipe and removes all steps (and clearing your recipe is something you can undo as well).
You can save a recipe to reuse later with the Save Recipe button in the Recipe toolbar (looks like an S). A new recipe will be created in your library, and you'll be able to give your recipe a name.