When a consumer makes a decision to use a company to buy products or services from, trust is a big part of it. Everyone wants to feel that they can trust the retailer to give them a product or service that does what it should and that they have the support when they need it should they have any issues.
It may be that you can build up this trust over time with continued business but for new customers you need to market your ethos. Promoting other clients that have used your company will give people confidence. Also showing case studies and recent projects can allow your customers to find out more about the type of service you offer. If possible, giving guarantees and / or warranties is another way to build up trust with your clients giving them peace of mind, should anything go wrong it can be quickly and easily rectified.