Sizing
Rings are made in your size. Measure with a jeweller's ring gauge on the finger you mean, late in the day when hands are warmest; if your knuckle is bigger than the base of the finger, the knuckle decides.
Signets and wide twisted bands sit snug, so go a half size up from a slim band. The pinky signet is made for the little finger, the L'chaim signet for whichever finger you raise a glass with.
The bar spoon cuff is an open oval made to an average wrist, eased on over the side and closed back. Tell us your wrist and we make it to that. The braided bangle is closed and passes over the hand, so it's sized to the hand, not the wrist.