There are many designers on wattpad, you can find them in the or in books that are . You may also find designers just by looking at other books, many authors will mention who makes their book cover in the description. Here are some tips on finding a designer who is a good fit for you.

one. know if their open to requests. 
Most wattpad users have a life outside of wattpad — a job or school —so they might not be available to make you a cover. Most designers will only take request in their cover shops, whether it be a book or a thread. If it says "open" you should be good.

Why this matters: Some users have closed shops, and people still request and ask when their cover will be done. Some people don't seem to care, be the nice person who cares. If you don't know if their open, just drop a question.

two. look at their examples. 
Really look at them. People have styles and sometimes it can be subtle. What you're looking for is a similarity between their covers what they tend to do in image treatment, color, and text placement. Also look at what genres they tend to make covers for.

Why this matters: Some users like to request from people who's covers they like. And while this is a good practice, sometimes what they make isn't what's best for you story. 

three. know how they work 
If you're in their thread, or their book shop, look at what requests they reject and accept. A lot of designers know what they're good at and what they're bad at and they want to make you good things.

Why this matters: It saves you time. A lot of users don't like it when people go around making request for the same graphics. In the threads people have "thread hopping" rules.