Ask yourself if you have a deadline, when would you like to have it done by? If you do it on a whim things can take longer than you want it to. Once you know roughly how long you want to take, break it up into building stages - preparing the dresser, allocation of materials, testing for fit, understanding the process, etc. Then start the build of the background and if you want it to look good - take your time. It probably be the longest time spent on any part of your project.
If you are worried about your abilities artistically, backgrounds are more about a depiction of nature, so study it. Look on google at how rocks look or whatever you are trying to replicate, look at other people's work - draw inspiration.
A project is not so much about physical ability as it is also about your knowledge, confidence and understanding of the process.