Before any kind of usability testing, decide with your team what the goal of the testing is.
Designers often don’t feel ready to put their product out for testing in the middle of the design process. What you can do here is create prototypes to test users.
Comparative testing allows users to compare two sets of designs or features. Exploratory testing allows users to suggest what features they are looking for in a particular product.
Limit the number of tasks you expect users to complete. Give them clear instructions on what they are supposed to do and allow them enough time to understand and complete the task.
In a controlled environment, you can monitor users’ tiniest flinches and gulps as they try to use the product. These valuable observations can then be included in the design process.
As usability testing is performed at regular intervals, continually incorporating the feedback received and improving the product will result in a more evolved, refined product with fewer iterations.