You'll need to go through the following key stages to make your own board game:

1
Getting and developing the idea.
2
Designing the layout, game play, and rules.
3
Creating a prototype ready for testing.
4
Game testing in live play situations to gather data and feedback.
5
Analyzing the results of the play tests.
Like any other creative endeavor, designing board games takes time, effort, making and learning from mistakes, consistency, honest feedback, and all the other things that go into bringing creativity to life.