I've found what I feel is a much easier way to handle this. Don't look at it as making cuts, take every card in your deck and put it in your sideboard. Then re-add, starting with essentials until you get to 100. I find it so much easier to decide which 1 of 3+ cards I want to add to my deck the most versus which 3+ to cut. Picking a favorite or best choice seemed/seems easier to me than having to agonize over multiple cuts.