It has been proven that the first idea is not necessarily the best idea. Even though it can be difficult to see past the first design you have, forcing yourself to think outside the box and come up with alternate designs will help you to find the best design. This will happen either by helping you find a second or third design that is better than your first or will help you see why your initial design is actually the best one.
We recommend spending at least double the time you used to come up with the initial design to come up with alternate designs.
You can do this for major design decisions, such as should we lead them through making a graph or should we just show all possible graphs at once, as well as smaller ones, such as where to put a button.
There are two trade-offs in choosing a medium to make a design in. The first is the time it will take you to make the design. The more faithful the design is to the real application, the longer it will take you, even if you mock something up quickly in code. When you are early in the design process, making your designs quickly so that you can get feedback on them before you invest too much time in them is ideal. When you are later in the design process, making your designs higher fidelity can be helpful to refine details and get specific feedback from users.
The second trade-off in choosing a design medium is how it is perceived by your users and hence, what kind of feedback they give you. If a user thinks that you have already put a lot of time into a design, they are unlikely to tell you that nothing about the design works for them and that you should start over. Users are more likely to give more honest feedback if the designs look less polished.