Just start!
One of the main barriers I come across, is researchers holding off sharing their grant ideas with colleagues because they don't feel the idea is well enough developed to share. This is understandable, because, frankly, to have got to where you have in life it's highly likely that you have a decent quotient of perfectionist tendencies and, as part of an intellectual sector feedback can easily be taken as criticism. Many of us feel a sense of shame when receiving feedback, perhaps that we should have thought of that, or feelings of not good enough can bubble up, even amongst the most confident. This is often compounded by many colleagues not being talented givers of feedback; they intend to be helpful, think they are being helpful, but their tone and phrasing can leave a lot to be desired...
I won't repeat here how to seek feedback, because that was covered in this article, suffice to say approach feedback as information input, seek it in phases and always remember you are the captain of your own ship!
In this article I simply want to implore you to go for it this year! Obviously submit nothing short of the best possible application that you can put together, but in getting to that point be cognisant of when feedback and refinement is starting to make very little impact on the strength of the final application. If you share ideas and seek input from trusted colleagues early it can make a material difference to your thinking, how the ideas are put together, and how strongly they are communicated in the written application. These fresh perspectives can help you see gaps, and inconsistencies early on that strengthen the idea, and the way you describe it, well before you start the work of putting pen to paper. Having fresh perspectives will also enhance the efficiency of your writing because sharing with others supports your own thinking and ways of communicating, often very complex ideas. Typically, once you have produced a thorough final draft, it's really difficult to change your thinking; much better to start with something tested and much stronger!
If you're struggling to get started and need an external support partner, or resonate with the comments about shame, or not feeling good enough, when logically we know by anyone else's measure we're doing absolutely fine, you might like to check out these grant coaching services, or the personal coaching we're developing under the Artemis Project umbrella.