For the smoothest interaction between Netbeans and Eclipse projects (i.e. when copying Java files), name your Java packages the same in both IDEs.
Always create a JPanel form (not JFrame form).
Use ONLY layouts that are native to Swing, such as GridBagLayout and BorderLayout. If you don't want to set a layout, use NULL layout (which is not the default).
Sooner or later, you will feel that you have to learn it anyway, so voila => GridBagLayout Tutorial