First thing is that affiliate marketing takes way longer to make real money than the YouTube gurus make it sound. Most people quit after a few months because they're not seeing results, but it genuinely takes 6-12 months of consistent work before you start seeing decent income. You need to build an audience first whether that's through a blog, YouTube channel, social media, or email list, and that doesn't happen overnight. Don't believe anyone promising you can make thousands in your first month unless you already have a huge following or you're spending serious money on paid ads.
Second is to only promote products you actually believe in or have used yourself, because your reputation is everything in this business. If you recommend garbage just because it has a high commission rate, people will stop trusting you and your conversions will tank. It's way better to promote a $20 product that genuinely helps your audience than a $500 course that's overhyped junk. Also, different niches and products have wildly different conversion rates - some affiliate programs pay high commissions but barely anyone buys, while others pay less but convert much better.
Third thing is that you need to understand the rules and regulations, especially FTC disclosure requirements. You legally have to tell people when you're using affiliate links, and platforms like YouTube and Instagram have their own rules too. Also, don't put all your eggs in one basket with a single affiliate program because they can change commission rates, shut down, or kick you out at any time. I've seen people lose their entire income overnight because they relied on one program. Diversify across multiple programs and focus on building your own audience that you control, not just driving traffic directly to affiliate links.