If you want to do the deeper dive you can use the Sheldon grown gear calculator and you can see where the overlaps are from big to small ring. If I have a very flat ride - I will put on a 12-23 cassette which gives me a super tight shifting ratio. If I am climbing then I opt for a 12-27 or even 13-29 cassette - depending on how many climbs are over 10% grade. If you are using Shimano or Sram - you do not need to buy Dura Ace / opt for Ultegra or even 105 cassettes to save you money. The other thing is that many do not really need an 11 cog - start your cassettes with a 12 or even 13 if you are climbing a lot those days.
https://www.sheldonbrown.com/gear-calc.html