1) I have a nice ceramic knife for sushi since it keeps its edge nd is light and easy to handle, I had used my Kitchen Aid Chefs and Utility knife (after Resharpening,-always use the sharpest blade possible for quick and easy cutting) alternately for simple straight even thin cust use a mandolin as you might for potato or onion slices)

2) lay the cucumber slices on a clean cotton towel (flour sack is best)then pat dry - lie in an even row and apply a layer of rice - genly flip over (or use asecond mat to sandwich and flip). Add filling as desired and roll as usual.

Good Luck!