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Two-hand tapping on an electric bass can be used in a multitude of ways. One way that can be employed is the creation of improvisations in the upper register with the RH (right hand) while playing a bass line in the LH (left hand). One of the best ways to hone this skill is to play short ostinatos in the LH while slowly increasing the complexity of improvisations in the RH.
A great way to start acquiring this skill is to play a bass line that simply iterates the pulse in a very literal way (e.g. jazz swing), rather than being syncopated (e.g. funk). That way any form of syncopation can be restricted to the right-hand improvisation (see Fig.1 in the link above).