How to easly determine the coorinates on a TFT LCD

Hey guys I would like to know how all of you are determinating specific coordinates on a TFT LCD regardless of size.

How do you place text, pictures, buttons,... on the right coordinates, because for me it is realy time consuming and stressfull to constantly upload a sketch and see if I got coordinates right or do I need to change them.

Is there an app that can mimic the x and y size of LCD and to be able to get x and y output based on my size of text, picture,etc

Thanks for all the answers BR

I make a debug screen. Its basically just a blank screen that tells me where i'm touching. After I judge by eye where I want something to go, then I write down the coordinates.

Doing this will put me in the ballpark of where I want to be, then it is just a matter of fine tweaking.

I just use Windows Paint, create an image the size of my TFT eg 320x240 or 800x480, zoom several times and add grid............. You can design pixel perfect accurately, especially if you want to use an image overlaid with pseudo buttons.... It rather conveniently displays coordinates too ;) :P.