If you have your own domain name and are a premium member, you create your subdomain with that account
ie SuesWebDesigns.suesman.net is a subdomain of suesman.net which is a premium account.
You can have up to 10 Domains on a premium account for just $12.00 a month, Much less if you are willing to pay for it long term. With a Years hosting package you pay $199.00 and you get the domain name for free.
5 Years $4.99 $299.00 Save $421.00!
This is an awesome deal and you don't have to worry about monthly payments or yearly renewal of your domain name. If you arent a premium member, I strongly suggest you become one.