Yeah if you jointly earned from signature campaign and trading then I don't think you need to find other ways to earn bitcoins as both of them will give you descent income regularly.
Though these two are the best ways to earn bitcoin but still if someone is willing to keep earning bitcoins regularly he will have to develop some skills in him as signature campaigns cannot be forever nor trading can earn you profits everyday, so someone should always has another back up option.
The best way to earn the bitcoin is to do a proper job and get paid in the bitcoin or you can buy the bitcoin.