First of all, the freelancers need to have a portfolio and a website of their own. Or at least one of them or even more. Having experience counts and you want somebody to build your website fast and good, right? Having a too low or too high price may also counts. You need to tell the person what you want to put on that website and the designer need to add all the features. If you use a CMS like Joomla or Wordpress and there are no extensions to do some features and the website builder needs to develop them it's even better, but first of all that person need to understand perfectly what you are telling him or her and that person needs to give you some feedbacks about his or her understanding and the work done.
Also, the frelancer need to be available at least to answer you. Maybe that person is busy or sick and he or she may not responde fast, but you should know the situation.
