It depends on what *kind* of marked deck you want/need. Do you need a deck that gives you the number and suit only? Number, suit and position in the stack? Suit only? Red/Black only?
For suit only and Red/Black markers, you can use shading (use a Sharpie and smear it slightly) using something near the corner, but not at the corner to throw off the eye. Bee decks are a bit difficult to use since the design is really only open to minute markings, which, for.a guy with not-so-great eyesight (like me) it can be a challenge to read them and almost impossible to read them when using a gaffed blindfold or blindfold peek.
There's lots that you can do with these more limited marking systems and I leave that to your imagination.