Question about playtests

Hi everyone, I’ve been working on my RPG Men-At-Arms on and off for several years, and I’m finally getting ready to release an early playtest version to gather feedback on its ideas and mechanics.

For those of you who have participated in or released public playtests before, what do you typically expect to see included in a playtest package? Are there any specific materials, guidelines, or approaches that make the process smoother or more engaging for players and GMs?

Thanks in advance for your advice!