How to make a proper resizing script?

I was working on a game earlier today and realized something when I went to test it on mobile, even though a image I had in studio looked square when I had the udim using the scale values instead of using the offset values, it came out looking very warped on my phone. I already knew that this happens but had never run into it before because most of my gui's just used the full screen anyways. Is there any way that I could make it so that the Udim2's offset values automatically change when the screen size changes?

This is all I have so far:

script.Parent.Size = UDim2.new(0,?,0,?)
script.Parent.Parent.Changed:connect(function(property)
	if property == "AbsoluteSize" then
		script.Parent.Size = UDim2.new(0,?,0,?)
	end
end)