How to test products effectively
We evolve by testing and measuring. This is how we do it, from the very early prototypes all the way to products.
Step 1: Get feedback ASAP, regularly.
Don't design in a bubble. Develop a culture of testing amongst your peers by sharing incremental progress and encouraging honest feedback. It'll will also help shape the idea collaboratively.
Step 2: Make prototypes that you can test digitally (if relevant).
Test a realistic flow, fast. The key is to have a focus/hypotheses to test and to keep it simple. There are many tools available to aid digital prototyping but here's a good place to start: use Sketch (to design and build your interactive prototype) and usertesting.com (to get feedback from people using it). More information on how to create an effective user test here.
Step 3: Conduct casual interviews.
Observe people interacting with your product. Through effective observation, you can interpret the feedback that your user isn't saying. Being casual helps your user feel as comfortable as possible allowing them to give more honest feedback. Remember to follow their actions more than their words (people tend to be polite!). You can get more tips here.