What advice do experienced tradespeople have for someone just starting their own business with limited income?

This is where most start. Truth is, there is not a magic answer, you will be very busy and have to do a lot of the work yourself in the beginning. But one thing I did was constantly gain new friendships with other contractors and subs. Do good work and higher these new business partners to do the same quality work you do and then step back and manage and keep going.