Eliciting the best work from your employees is the mark of an effective leader. But, effectively communicating what exactly you expect from them can be difficult.

"Unclear expectations lead to inefficient processes and subpar performance," says Christine Lotze, a partner at Philosophy IB, a Florham Park, N.J.-based management-consulting firm that specializes in changing workplace behavior. "People get frustrated because their work isn't valued and ultimately the company suffers."

You can avoid that confusion with these four tips to communicate your expectations clearly and effectively:

1. Reinforce your expectations. As with any conversation, you should use simple and direct language when communicating your expectations. "The key to effective communication is simplicity and repetition of the message," Lotze says. Hearing your expectations once won't make them sink in -- they need to be regularly reinforced.

For example, you might track progress in monthly check-ins, or call out employees that are meeting your expectations exceptionally well. When you do, reinforce which expectation you're highlighting and what they've done to meet it. That repetition will act as a reminder and clarify the types of behaviors you're looking to see from employees.

2. Explain who, what and how. To communicate clear expectations in a constantly changing startup environment, make sure that employees always know what you are trying to achieve, how you plan to get there, and who will do what to reach that outcome. "Most failures can be linked to a gap in clarity about one of these three components," Lotze says.

By clarifying expected outcomes, roles, and processes, you give your team all the tools they need to bring your vision to life. "If you don't explain how your vision is linked to what your employees need to do, you'll get a lot of great ideas with no execution," Lotze says.

Related: Why the Best Managers Ask the Most Questions

3. Notice what the work environment communicates to employees. For employees to meet your expectations, the work environment has to support the behaviors you want to see. "Every element of your culture must reinforce the expected behaviors you outline for your employees," Lotze says. If the expectations are at odds with the environment, your employees won't be able to meet them -- even if they're trying.

Effective expectations are supported by your reward system, as well as your company's structures and processes. For example, if you expect employees to take risks, then you need to celebrate those who do, and establish a work flow that allows for failure and experimentation. "You have to practice what you preach," Lotze says.

4. Take a personal interest in your employees. Your employees come to the workplace with their own wants and needs, so getting to know each person individually helps you ensure that they understand your expectations and feel motivated to meet them. "By really understanding what makes them tick, what gives them energy, and what challenges they are facing, a leader can much more effectively drive performance and change behavior," Lotze says.

Take the time to establish an emotional connection with each of the people you manage. Ask what they're struggling with, what they're working toward, and what excites them about the work they're doing. Knowing what motivates them will help you frame your expectations in a way that matches their career goals.

Related: What Really Motivates Employees? [Infographic]