Upload your real venue layout
Upload the venue's own empty floor plan — a PNG or JPG, up to 10 MB — and then work directly on it: drag an empty area to draw a booth, drag an existing booth to move it, and click to select and edit. The booth coordinates key off the uploaded image's aspect ratio, so the layout on screen matches the actual hall; re-uploading a differently shaped image clears the booths, which keeps the map honest to the venue.