Regular gardening tools are good enough for beginners, and a pair of scissors or secateurs can go a long way to keep a bonsai in shape, but specialized tools are better to work more precisely. This page will list the most useful ones.
Some of the tools in the following pictures from 2020 have been gifted to me in 2005 and they were already old at the time so they can last many years.
Pruning shears are used to trim small branches, they are fast and precise.
Long shears are also used to trim small branches, especially the ones inside a tree where the previous shears cannot reach as easily.
A branch cutter is used to cut bigger branches and leave a cleaner cut than regular garden secateurs.
A knob cutter is used to completely remove a branch and improve cicatrisation with its concave blades.
A jin plier is used to shape dead wood by tearing parts of a branch. They are also useful when wiring a tree.
A wire cutter is used to cut aluminium or copper wire used to shape branches.
The one pictured here is not a specialized bonsai tool and it is less convenient to remove wires from a tree.
The rule is thumb to wire a branch is to use a wire size that is about 1/3 its diameter for copper and 1/2 for aluminium.
Various sizes are needed to bend small trunks, or primary, secondary, and tertiary ramification. For aluminium wire a good range would be 4.0mm, 3.0mm, 2.0mm, and 1.5mm. A wire can be doubled when a bigger size is not available. In this picture I also have 1.0mm wire but I sheldom use it for bending and more as guy wire.