As one of the many who works more than one job I have to say there are challenges and benefits! Most certainly it takes planning, patience and perseverance!
Common Side Hustles:
Seasonal : (typically retail, hospitality) Hotels, Resorts, Customer service, Sales
Skilled: (freelance, contract for hire, commissioned work) Tutoring, Massage Therapy, Event Planning, Photography, Web design, Personal training
Both can certainly give your income a boost, and even allow you to do work that you enjoy! Skilled jobs usually have a bit more longevity, flexibility and sustainability.
For me, being a part time Massage Therapist it truly is my passion. While it is not wholly driven by income I do rely on the money made doing this work.
Working two jobs, no matter the type definitely takes a toll. You may find that other areas suffer. Keeping up with housework and chores, spending time with friends and family.
Should you decide to have a side hustle, try not to over commit yourself. If you do not balance your time effectively, you will have a difficult time lasting long enough to benefit from the second job.