Write down your idea. Be specific if you can, but don't be overly complex in either your language or description. If you are able to, try to draw the idea yourself or find images that are similar. Even if your drawing is very rough, a sketch or an indication of layout is very helpful to an artist who is trying to interpret your explanation.
Search for artists and illustrators and compile a list of possible candidates. There are websites that display the works of many artists, and browsing through one of these sites may be to your advantage. You must look for two main qualities in an artist. First, you must determine if you like the artist’s overall style. Second, you must determine if the artist typically draws the type of work you want illustrated. For instance, an artist who typically draws portraits may or may not be good at landscapes. If you need a technical drawing to illustrate in invention idea, you may not get a good result from an artist who specializes in abstract artwork.
Determine if the artist takes commissions. If you are looking at an artist's website, most artists make it clear whether or not they are taking commissions. If you are not sure, contact the artist and ask if he is taking commissions. Eliminate any artists who are not taking commissions from your list.
Contact the artists on your list. You need to find out how much each one charges for the type of drawing that you want and if the artist is willing to draw your idea. Some artists may not be interested in drawing your idea for a variety of reasons. Eliminate any artists who are not interested from your list. Write down the amount that each artists charges and what each artist is willing to do, so that you can compare and determine which artist will best suit your needs.
Contact the artist that you would like to commission. You will need to find out how to give the artist the necessary information to draw your idea and how the artist wants to be paid. If you are planning to use the drawing for commercial purposes, you may need to make further agreements with the artist.