I think it’s funny how 1500 is the amount of extra income you mention because that’s what I’m shooting for! If I can make that much more each month to supplement my regular income, I will have almost all of my school debt payed off in one year! I’m really motivated. I use Mechanical Turk with Amazon to perform menial task and get a few extra bucks. I also use Varolo which is a fairly new idea. I really think it has potential. If you don’t mind me promoting it, here it goes.
If you’ve been passionately collecting something over the years, this may well be your route to extra income. Be it comic books, records, stamps or even vintage clothing you picked up from second-hand stores, the chances are likely that there is someone out there who shares your passion. Whilst sites like eBay and Amazon are ideal for generic selling, if your collection consists of more niche items, you may need to use a more specific platform.
Most of us think of investment income as just the cash flow we get from bank interest, bonds, share dividends and property rents, some of which comes via a super pension.  But a more complete view is to also consider how growing the value of your investments can add to your spending potential.  This total return approach generates income from both income and growth to optimise spending from your portfolio across all market cycles, aligning cheap and expensive investments to your goals.