Impact vs. effort is a good way. Concerning deadlines, I've found the great tool that helps to work with tasks, their order, due dates, and deadlines. GanttPRO (https://ganttpro.com/) is a professional PM platform that will assist you in staying productive and get all things done.
Urgency in my definition is something that important & must be done faster, so when I'm missing the urgent stuff it will cause the effect and the effect can be bigger if we keep missing that.