When forming a board of directors how do you provide equity for lead director vs other seats?

Whoa. As a private company (a startup), you form a Board of Directors by way of investors.
Otherwise, you and your primary team members (with the most equity) effectively comprise your “Board” (depending on how you set it up).
Keep in mind, the CEO works for the Board. So you don’t want nor have an actual Board until you have a reason that stakeholders should have that oversight.
For example, most don’t realize that Amazon is not remotely Bezos’ company anymore. He only owns like 11%. He works at the discretion of the Board; which, granted, isn’t likely to replace him. This is by the way why Zuckerberg is considered very differently; he’s structured things so that Facebook is in many ways his company.
When you take on investors and part with substantial amounts of equity for that (10%+); part of what you have to negotiate terms over is Board seats and the various implications. You can certainly, for example, get an investor on board who has 20% equity but NOT a Board Seat (meaning they wouldn’t have that first degree of decision making about the CEO and major decisions… however, some things need to be voted on by all shareholders and so they’d still have a major say). Likewise, you could take on an investor for 10% and get them on the Board.
Before investors though (or being a Public Company), there really is not reason to have a formal BoD comprised of others (beyond yourselves) – you’re essentially just empowering people to decide things over you…. why would you do that without their investment?
What you do want to set up is a Board of Advisors. Use something like the FAST agreement to help structure that.
You’re allocating .25 – MAYBE 1% to people (all vesting after a cliff and over time; in exchange for clarity about what they’re doing for you), to get them on a formal Board of Advisors.
You’d still have monthly or otherwise regular meetings, and they’d help, but they don’t have control over the company.
(all that, briefly for the sake of thinking about it… of course there are a ton of legal, fiduciary, and other considerations that might make you do things differently. I’m generalizing)