The reason a list feels overwhelming is that everything on it appears equally urgent when nothing has been scored. Scoring removes that, and the effect is immediate: most lists resolve into three or four things that genuinely matter and a long tail that can wait indefinitely without consequence.
Cost means what the problem actually takes from you. Money lost, hours consumed, customers affected, or risk carried. A slow invoicing process that costs two hours a week is expensive. An ugly page nobody visits is not, however much it irritates you every time you see it.
Effort means honest effort, including the time to learn whatever you do not know and the time to fix it afterward when it does not work first time. Whatever figure you first write down is usually low, and the ratio between items matters more than the absolute numbers.
Work high cost and low effort first, without exception. These are the fixes that change something material within a day, and clearing them builds the momentum to reach the harder ones. Businesses that start with the largest problem frequently stall there and complete nothing.
High cost and high effort comes second, and these need scheduling rather than intent. Anything that takes more than a day will not happen in gaps between other work, and putting a date on it is the only reliable way it gets done.
Low cost and low effort is where most people actually spend their time, because these items are satisfying and quick. Do them in a batch when you need an easy hour, and never at the expense of the first category.
Low cost and high effort should be deleted rather than deferred. If it costs little and takes a long time, it is not worth doing, and leaving it on the list makes the list heavier without making it more useful. Removing things is part of prioritising.
Watch for the item that unblocks several others, because scoring will underrate it. A single change that makes four other problems disappear is worth more than its own score suggests, and you will recognise those when you see them even though no formula catches them.
Reassess when circumstances change rather than on a schedule. A problem that was minor becomes urgent when volume doubles or when somebody new joins, and a list scored six months ago is describing a business that no longer exists.
Then accept that some things stay unfixed permanently, which is the outcome people resist. A business with no unresolved problems has either solved everything, which is not possible, or is spending time on problems that did not deserve it.
Write the list down before scoring anything, because holding it in your head is what makes it feel larger than it is. Most lists that feel unmanageable turn out to have eight items on them.
Fix the root cause rather than the symptom where the two are distinguishable. A problem that recurs after being fixed was not fixed, and repeating the same repair quarterly costs more than addressing what causes it once.
Set a limit on how many things are in progress at once, because three half finished fixes deliver nothing while one completed fix delivers something.
Revisit the deleted items once a year rather than never. Circumstances change and something that was not worth doing at low volume occasionally becomes worth doing later.