Make the "render in background" the default option for rendering. I sometimes start a render and then think i want to change something and then i forgot to push that button.
Make the shadow strength possible to adjust to more or less shadow. Sometimes i think there is too little shadow and it kind of looks like my model is floating.
Shadows are calculated from the environment. To make the shadows darker adjust the HDRI in the editor by adding a pin over the existing light sources.