The person who uses drawing to talk to the audience through visual presentation is called an illustrator.  Although the market is flooded with art service providers only a few like toronto illustrations can do it the way you want it to be.   Because of this confusion in the industry, you should put into considerations the following guidelines. 

 The experience of the illustrator in the business.   The experience of the service provider is very important when you are looking for quality illustration services.   Because of being exposed to many customers that have a different specification for their work the illustrator get more ideas for doing the job perfectly.  

 The fame of the illustrator.  The best illustrator is the one who has no black spots in his/her line of job.   You should engage in consulting people that you know they have been using such services so that they can direct you to the most qualified illustrator. The illustrator that will be mentioned by many people is likely to do the best for you.   The testimonies on the illustrator's website can give you more info about the services of the illustrator.   Compare and contrast the weight on both the negative comments and the positive comments so that you will make the right decision based on the side with more weight.   The illustration services that has been captured by the reviewing site like BBB, Glassdoor and Yelp are the best for you to choose because a lot about the services will be displayed there. 

 The price of drawing.  The place you will take your ideas and the level of drawing required can make the illustration services to be high or low.  Move from one service provider to the next consulting about the price of this service so that you will find the one with flexible prices.   In most case low costing services tends to be of low quality. 

The quality of the customer services is also another factor to consider.  There is no way you can expect good services when the services provider is rude and not giving you time to explain yourself.  The illustrator who doesn't pay attention to your specifications on how you need your ideas represented and give you advises according to the experience s/he has is not the best.   The already done projects can help you make the best decision on who to hire for your idea visual representation.   Don't choose the illustrators who take long before completing the work given.You can learn more here.