I would suggest offering feature sheet design as well. Even just using the simple flyer templates in Publisher will allow you to create great looking feature sheets.
I come from a background in web design and graphic arts, so I actually enjoy this part of the job, and I get a lot of offers from within my office from people that want to pay me to this or that. There is *definately* a market for this type of work.
Also consider promoting yourself as a full service turn key type assistant: go take the pictures, upload them/or make arrangements for them to get on the MLS, and design and deliever the feature sheets to the brochure boxes. People that are producing don't have a lot of time for these chores. I also do a lot of digital editing to show owners what their house would look like if they cleaned up the front yard, repainted, etc. Now that people in my office know I can do this, I'm constantly getting pestered to "fix up" a house they have listed so they can take the picture back to the seller and show them the value in doing a little home improvement.*
*For the record, we don't use these edited pictures on the MLS, it's simply to help convince the seller that the curb appeal can be drastically improved with a few small changes.