In general, you want to prioritize keeping your hard drive focused on documents, photos, and some videos. So then you need to decide what worth leaving on your hard drive, and what worth storing in the cloud — as certain kinds of files shouldnt be kept in the cloud either. Normally, it comes down to privacy, which ones might ruin you if you accidentally lose them forever, and the general technical reliability of your long term storage solution. But if you are ever worried about losing anything...
