I simply signed the message so a buyer would know I have full access to the funds.
I like to use new addresses and try not to use the same address twice!
That means you are using exchange wallet or blockchain.com's wallet which generate new wallet address while you click on receive. But you can use the same address as long as you want as you have private key of the address. If you use same address it will be helpful for you in future if you face any issue on the forum about the ownership of your account, recover your account if hacked.
I am using an electrum wallet just using a new recieve address each time.