A workflow I generally use, creating a model with no user parameters just to get the idea out of my head and onto the computer. Then after prototyping (3D print), I will note the issues that I found, then in the model, create necessary parameters for updating the model with ease.
An issue I find with this is that the parameter window, when open does not allow me to select and change dimensions and their values. I generally create the parameter when I see the dimension I'm changing from a hard value, then I update the dimension to the variable parameter name.
I realise that the model parameters are given, but in a complex model, this can be hard to navigate if I can't recall the correct feature or dimension within.
My idea is that when the parameter window is open I can still edit a sketch dimension value in the 3D space or is selected in the parameter window to change its value to a parameter name. Also, when the window is open, selecting a feature in the feature bar will navigate to the corresponding feature in the model parameters, then I can change the feature parameters to a user parameter.