Every follower should be aware that the links on your site could lead to a commission of some kind for you. Even if you are making a simple social media post, you need to disclose that the link is an affiliate link in some way. If you do not disclose this fact, then you could out of compliance with guidelines issued by the Federal Trade Commission.
Research selling prices of items similar to yours. Look up completed sales or current listings of items similar to yours. Find the high- and low-end prices, and price your object around the median price level. If you want your item to sell quickly, price it at the low end. The condition of the item also affects the price. Items in poorer condition should be priced at the lower end. Also, consider how many listings there already are of items similar to yours. If many similar items will be competing with yours, you may have to set the price lower to get the sale.
Relevancy is the first qualifier of a quality link opportunity. The next qualifying factor is the authority of the opportunity. Since Google doesn’t update PageRank (PR) anymore, you must rely on third party metrics. I recommend you use Domain Authority (DA) from Open Site Explorer, Domain Rate (DR) from Ahrefs, or Trust Flow from Majestic to determine the quality of your link opportunities. You should use all three tools if you can.
Find work. When you first start out, you may have to accept work writing about a topic you don’t find all that interesting. You must keep an open mind and be willing to accept work that may not be in your desired field. However, as you continue to write, you not only learn about more topics, but you also build your reputation. With time, you can be choosier about assignments you want to accept.