I was assuming that you want to create a design of some sort and so you would need to place the frit accordingly. If you want a bracelet (say) an inch wide, you can make your mould higher (say 2″) and fill to the top. then just cold work the sharp edges off.
You could place strips of glass, or pattern bar in the mould to make the design. Pack tightly, fire to 850C and anneal for the thickness of the space in the mould.