Both those ideas work just fine. Many of us use diffirent methods, for instance, Michael Bush uses migratory covers, therefore he can just wedge the corners on one side in order to vent the top of the hive as well as provide a top entrance for the bees, which is what they seem to preferr anyway. I have a mixture of migratory and telescoping covers, on some hives I have vented attic boxes to help exhaust the heat and humidity, on some of the telescoping covered hives I have slots cut in the inner cover to provide an upper entrance as well as a vent, and I also have popsicle stick type shims on all four corners between the inner cover and the telescoping outer cover to provide ventilation without enough space for the bees to get through. And then in a pinch I have shifted top boxes slightly towards the rear to allow an entrance and exit along the front edge. As you can see there are many methods to achieve the same end result, work with what you have.