Cast on to a WIP

I’m working on my first lace project. The pattern instructs me to cast on additional stitches to begin the border. What is the best method to cast on to a work in progress?

Thanks for your help!

Usually a knitted cast on.

Knitted or looped castons are good for lace, but if you are a perfectionist like me you could do a provisional caston and then when you’re done graft the two rows together in pattern…