I would always google the company, this will bring up the company web profile - Website, google listing, trustpilot facebook etc - Anyone without such pages or any pages i would normally stay away from.
If you have a website and some were to go if ever required it gives you full peace of mind that you have chosen the right contractor.
Most people will now a days have reviews on either facebook, Trustpilot or google. Stick with these types of companies and take it from all other customer reviews. DO YOUR HOMEWORK
Hope that helps :)
Elite Renovations Group Ltd