Solutions Should Start Simply

Do not limit ideas for possible solutions. However, start with the obvious. Begin with simple, straightforward solutions. Leave the explanations as to why they won't work or why they are not the right solution to later. We will take care of that in Step 4. Use the solution criteria as a guide. Don't worry if a solution does not meet all of the criteria, just as long as it does meet a few.  Once the obvious solutions are all said, layer each of them with one layer of complexity. Make the simple a bit more complicated. 
But that complication can't be for it's own sake. It has to contribute to the completeness of the solution. The solution can become more complicated if it meets more of the solution criteria. A solution can be more complex if it makes the solution better. Complexity has to bring the solution one step closer to being the best solution possible. It has be worthy of its inclusion. Repeat the process with other solutions your are considering. Then go back to first solution and create more possible solutions by layering another layer of complexity and so on.
Spend time on deciding whether a level of complexity is worth it's inclusion. This way, complicated ideas are not discarded because they are simply complicated but because the benefits it brings are not worth it. By spending time on this, the time to stop layering complexity onto simple solutions would come naturally. This way both simple and complicated solutions are known and considered for evaluation.