Reorganizing a database objects

I am developing an application which uses a PostgreSQL database which is
located in a specific folder of a hard disk. I think that maybe it is a good
idea to reorganize the different objects that compose it and change the
location of tables, indexes and constraints. For example, tables can be
split among different hard disks and apply this same criteria with other
indexes and constraints. I am guessing this approach could improve DB
functionality but I do not have a solid base for my idea. Lets suppose that,
after some time, I decide to move some tables and indexes to another (one or
more) storage unit(s). How do I perform this change? Should I create a new
DB that reference such new locations (Tablespaces), backup the original one
and restore it to the new one? If this is so then it would be a big job to
create every object unless there is a tool to generate a script with the
necessary SQL commands to build the new DB.
I will appreciate any comment about my issue.

Respectfully,
Jorge Maldonado