How to List an NFT for Sale on OpenSea
Before being able to list an NFT for sale on OpenSea, you need to first set up an account. If you haven't done this yet, please refer to the article on how to do so.
This article will go over how to sell an NFT from a laptop, but will be very similar from mobile.
Step 1: Navigate to https://opensea.io/ in your browser, connect your Metamask and go to your profile.
Step 2: Select the NFT you want to list for sale. Select sell in the top right hand of the screen.
Step 3: Determine the terms of the sale. You can choose either a fixed price or timed auction.
With a fixed auction, you set the lowest price in (Ether) you are willing to sell your NFT for and if a buyer wants it, can buy it at that price. Note that it is free to list an NFT for sale and to lower the price, however, will cost a transaction fee to cancel a listing and raise the price. Notice you can set a time period for how long you want to list it for under "schedule listing" as well as sell it as a bundle along with other NFTs. You can even reserve the listing for a specific buyer. Also notice the service and creator royalty fees at the bottom (circled in red). The service fee goes to OpenSea and the creator royalty is set by the creator of the NFT. In this case, 2.5% of your sale would go to OpenSea and 5.0% would go to the creator.
With a timed auction, you can either sell to the highest bidder when the time expires, or have a declining price where the price declines over a set period of time. You can set a reserve price or the minimum price you are willing to sell for to a bidder. Something to note is that in a timed auction where the piece is sold to the highest bidder, bids are made in wrapped ether, not regular ether. Wrapped ether just is another iteration of ether on ethereum. Please refer to the article on how to use a decentralized exchange if you would like to learn how to swap for regular ether or other tokens.
Once you have set the terms of the sale, click "complete listing" and your NFT will officially be up for sale for the entire world to buy!