"do the most important tasks first then, if you have time, do some less important tasks"

yes; this is of crucial importance and even though it might be obvious to you; it is often not obvious to other people. As well - often tasks have vague importance. Where it might be hard to say which one is more important. In cases where the super important website deployment and some less important tasks are on the list, definitely it's easy to see the super-important thing taking precedent. but in cases where you need to choose between groceries, going for a walk, and checking facebook - it might be harder to decide. In that case - consider the task that can most easily be cut off. for example; it's can be harder to cut "a walk" in half because you might be halfway home. But it could be easier to cut groceries in half by only buying some of the groceries and rushing around the store.