Code all your events on one event sheet. Then, any later layouts can simply have an 'event sheet include' (right click, include event sheet in event sheet editor) to include the game events. This saves you copy/pasting events. Also, if you right click an existing layout and select 'Clone layout', it'll duplicate all the objects. You could then rearrange the objects to design a new level. (Cloned layouts have no events, it's intended that you include the original events)