Great question! There are a few methods, and none of them are perfect (that why I switched to Square Gift Cards)
My prefered method - it's not very pretty but it works - is to make Discounts in varying amounts and starting all of their names with Gift Certificate:
Gift Certificate $0.25
Gift Certificate $0.50
Gift Certificate $1
Gift Certificate $2.50
Gift Certificate $5
Gift Certificate $10
Gift Certificate $20
etc.
I'll make duplicates of some of them to get to inbetween numbers and go as high as my gift certificates go. You need the smaller ones in case someone has $3.25 left on a $50 Gift Certificate
Again, not pretty, it works, but it's not as simple as Gift Cards that automatically do it all, which I highly recommend
Hope this helps!
