Game Creation Guidelines/Refinement
This is the first of the iterated steps and, as the name implies, involves a bit of planning, pruning, tuning, and clarification of your initial idea so that you have a playable ruleset. If you don't have a full ruleset, hopefully you have at least a basic outline of your mechanic, or a further elucidation of your theme - something you can start to test or expand into a bigger and better game.
The First Refinement
When you make your first refinement, emphasis will be on making something that is at least testable. Your initial idea may be nothing but the thoughts "pirates, pork sausage, bidding mechanism," but you need to develop your objectives, perhaps your board, and start to hash out your rules. Every person has a different way to manage his/her project. Your design style may not be the same as anyone else's design style, and the degree of time you want to spend refining your game before you first play-test it may be very small or very large. For example, as soon as you have the idea for your pork sausage pirate bidding game, you crack open a few of the board games in your house, steal a deck of cards, call some friends over and start making it up as you go along. This is clearly a very hands-on and ad-hoc approach to the design of your game. You may, however, want to develop a full and tight rule set founded on the laws of probability and the eternal principles of the universe. In which case, you might cloister yourself for ten years on a mountaintop with nothing but a velvet painting of a crying pirate, a lifetime supply of pork sausage, and some spare change. This is a far more theoretical and hands-off method of refinement, and that is perfectly fine if that is the kind of person you are. Game design isn't a science. You still do what fits with your personal style.
This involves going back to the rules, looking them over, and applying the knowledge you gained in playtesting and evaluation. This can amount to a total redesign of parts or all of the game. Through evaluation you should know where and how the game should change, and the next phase of development and testing will tell you how those changes worked. Subtle tweaking over multiple testing sessions will end in a polished game, and (re)development is where your "lessons learned" are put back into the game design.