This is a "knotting" technique that shortens w/o cutting. It keeps the blinds evenly level when adjusting because I always pull one cord more than the other.
Lower the blinds to windowsill and make sure blinds are evenly level. If you shorten the cords while blinds are pulled, there won't be enough cord to lower the blinds after.
Wrap cords around like above.
Move ends to between the fingers.
Pull the ends through to create a loop.
Move ends to between the fingers & pull through again. Repeat until you're close to the end. When you run out of cord, just pull all the ends through to tie off.
Adds a decorative touch. Enjoy!