Get as close to the money as possible (for me this was B2B tech sales) and look for big pain points that you can solve. Typically the bigger pain points are around things that are costing these companies lots of money, either directly or indirectly with opportunity costs.

If you can legitimately solve a $10,000 problem for a company or bring them $10,000 in revenue, it's not hard to sell them on $5000 in consulting fees.

Hourly consulting can be "quick money," but at least for me one offs aren't really worth it. You often spend as much time or more with small clients for little gigs as you would with bigger reoccurring clients that you understand more and more over time, making you even more invaluable to them. If you can't get your foot in the door with a client any other way than a few hours of consulting, then do it, but relying on little consulting gigs to eat gets stressful fast.

I recommend reading Personal MBA or Pumpkin Plan for tips on using the 80/20 rule to make "bigger money" faster. It's not magic and it takes a lot of hard work, but if you're going to work hard you should also work smart.

If you want more specific advice on how I built my consulting practice, message me.