Choose a 'buyer's agent.' A buyer's agent is a real estate agent that negotiates for you, not the seller. The agent should make sure that you pay the lowest price - not that the seller makes the biggest profit. Beware of real estate firms that claim to work for both sellers and buyers. They tend to charge commissions from both sides, so that you end up paying more, and the seller profits less. These 'dual agencies' give least protection to you and the seller.
Carolyn Young RE/MAX Premier, many Denver real estate agents and real estate firms operate in this manner. Avoid them at all costs.
Find an agent that provides free house inspection services. Not all Denver real estate agents provide free professional home inspections, but you can find those who do. The willingness of agents to subject their properties to through inspection is a sign of sincerity.