Reparenting

[brcain]

So first position widgets and then apply a layout, not the other way round.

That's probably it. I'm used to desigers that also support a top-down approach ... which can be useful for refactoring.

Maybe you have a wrong approach here? Try to first build a hierarchy of objects you need, apply layouts to each hierarchy and only then position the groups as they should remain and as the last point, apply the layout to the form itself.

Does this approach work well with redesigning an interface?