Describe in as much details what you’re looking for both regarding the subject and the technical specifications/limitations
Mention the intended use
Being very specific ofwhat you’d like and trigger someone’s interest usually offers the best chances of requrest being picked up
It’s not uncommon to offer something in return, mention the options or discuss in private.
“I have no budget and this should be done for free” is usually not a good pitch
Be aware that creating ANSI artwork (depending on dimensions) is usually hours of work. The chances of getting someone drawing a full BBS menu set for fun is quite low
Supply reference images or other ASCII/ANSI artwork that aid in illustrating what you’re looking for
Most (but not all) artists to be properly credited for their work
