You must need to use the affiliate product before you promote it. Because once you tried that product, you understand the ups and downs of the product than others.
Simply create a blog post as if you were recommending a product to your best friend. Keep it conversational and casual, and make sure you highlight the benefits of using that specific product.

You need to be very active daily on Instagram to achieve this. Affiliate marketing without followers is nearly impossible.
Let’s look at an example. Say I sign up for and get accepted into the Pit Boss Affiliate Program. I go to the Pit Boss affiliate portal and they give me unique links (for grills, pellets, etc) that I can use on my blog. I post a recipe using my Pit Boss on my blog and include an affiliate link to the grill I used in various places on my post. Thank link goes to the product page of the grill I used. Someone reads my blog post and decides they want the same grill I have so they click my affiliate link and it takes them to that grill on the Pit Boss site. They purchase that grill. I get a commission on that sale because I assisted in that sale. I have a full time job that I’m not ready to leave. So I use affiliate marketing as a supplement to my income. It’s my side hustle. Sometimes it’ll take care of my gas money for the month and sometimes it’ll take care of the mortgage and my car note too. I’m not at the point where I’m making six (or even five) figures yet. But a LOT of people use affiliate marketing as their full time job and sole source of income and I believe it. Maybe one day I’ll be at that point but until then, it’ll remain a fun side hustle.