This seems to be a trivial point to American founders, but somehow in Europe I still run into startups that hire fundraising advisors to "accompany" them in fundraising.
Fundraising is such a key part of a startup's life that it should never be outsourced. In the modern world there's absolutely no reason why a startup should approach a reputable VC via a fee-collecting fundraising advisor or consultant.
If the founders need someone else to help them communicate their vision, articulate their business plans or figure out the capital required until the next round, they are most definitely not gonna be successful one way or the other. It's better spending the time and effort elsewhere, such as in a big corporate or a research institute.
Also, the founders should always be fundraising, meaning that even during the time you don't need money, you should always keep the VCs you respect and want to work with updated about your progress, in a light way. Fundraising is a sprint in its obvious form, but without the everyday training you will never win in that sprint to come.