Nip any growth that appears on the trunk and branches. Suckers can best be described as growth that is too heavy on the trunk or branches. Wiring is really the art of Bonsai to me. It is bending and twisting the branches to give the Bonsai its wonderful shape. You to this after you've pruned, nipped, etc., and its essential branches remain.
Copper wire is flexible and comes in many sizes.
The lower the number, the heavier the copper wire. Wire an evergreen, such as a juniper, only when it's dormant. If you do it during its growing period, you can damage the tree. During the winter months, my juniper is placed in the garage and is dormant. I alternate winters.